chore(java): rename EnumString to MetaString (apache#1516)

## What does this PR do?

This PR renames EnumString to MetaString

## Related issues
apache#1514 


## Does this PR introduce any user-facing change?

<!--
If any user-facing interface changes, please [open an
issue](https://github.com/apache/incubator-fury/issues/new/choose)
describing the need to do so and update the document if necessary.
-->

- [ ] Does this PR introduce any public API change?
- [ ] Does this PR introduce any binary protocol compatibility change?


## Benchmark

<!--
When the PR has an impact on performance (if you don't know whether the
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go/fury/type.go

@@ -403,25 +403,25 @@ func (r *typeResolver) writeType(buffer *ByteBuffer, type_ reflect.Type) error {
 			r.typeToTypeInfo[type_] = encodeType
 		}
 	}
-	if err := r.writeEnumString(buffer, typeInfo); err != nil {
+	if err := r.writeMetaString(buffer, typeInfo); err != nil {
 		return err
 	} else {
 		return nil
 	}
 }
 
 func (r *typeResolver) readType(buffer *ByteBuffer) (reflect.Type, error) {
-	enumString, err := r.readEnumString(buffer)
+	metaString, err := r.readMetaString(buffer)
 	if err != nil {
 		return nil, err
 	}
-	type_, ok := r.typeInfoToType[enumString]
+	type_, ok := r.typeInfoToType[metaString]
 	if !ok {
-		type_, _, err = r.decodeType(enumString)
+		type_, _, err = r.decodeType(metaString)
 		if err != nil {
 			return nil, err
 		} else {
-			r.typeInfoToType[enumString] = type_
+			r.typeInfoToType[metaString] = type_
 		}
 	}
 	return type_, nil
@@ -519,23 +519,23 @@ func (r *typeResolver) decodeType(typeStr string) (reflect.Type, string, error)
 }
 
 func (r *typeResolver) writeTypeTag(buffer *ByteBuffer, typeTag string) error {
-	if err := r.writeEnumString(buffer, typeTag); err != nil {
+	if err := r.writeMetaString(buffer, typeTag); err != nil {
 		return err
 	} else {
 		return nil
 	}
 }
 
 func (r *typeResolver) readTypeByReadTag(buffer *ByteBuffer) (reflect.Type, error) {
-	enumString, err := r.readEnumString(buffer)
+	metaString, err := r.readMetaString(buffer)
 	if err != nil {
 		return nil, err
 	}
-	return r.typeTagToSerializers[enumString].(*ptrToStructSerializer).type_, err
+	return r.typeTagToSerializers[metaString].(*ptrToStructSerializer).type_, err
 }
 
 func (r *typeResolver) readTypeInfo(buffer *ByteBuffer) (string, error) {
-	return r.readEnumString(buffer)
+	return r.readMetaString(buffer)
 }
 
 func (r *typeResolver) getTypeById(id int16) (reflect.Type, error) {
@@ -546,7 +546,7 @@ func (r *typeResolver) getTypeById(id int16) (reflect.Type, error) {
 	return type_, nil
 }
 
-func (r *typeResolver) writeEnumString(buffer *ByteBuffer, str string) error {
+func (r *typeResolver) writeMetaString(buffer *ByteBuffer, str string) error {
 	if id, ok := r.dynamicStringToId[str]; !ok {
 		dynamicStringId := r.dynamicStringId
 		r.dynamicStringId += 1
@@ -571,7 +571,7 @@ func (r *typeResolver) writeEnumString(buffer *ByteBuffer, str string) error {
 	return nil
 }
 
-func (r *typeResolver) readEnumString(buffer *ByteBuffer) (string, error) {
+func (r *typeResolver) readMetaString(buffer *ByteBuffer) (string, error) {
 	if buffer.ReadByte_() == useStringValue {
 		// TODO support use computed hash
 		buffer.ReadInt64()

java/fury-core/src/main/java/org/apache/fury/Fury.java

@@ -46,8 +46,8 @@
 import org.apache.fury.resolver.ClassInfo;
 import org.apache.fury.resolver.ClassInfoHolder;
 import org.apache.fury.resolver.ClassResolver;
-import org.apache.fury.resolver.EnumStringResolver;
 import org.apache.fury.resolver.MapRefResolver;
+import org.apache.fury.resolver.MetaStringResolver;
 import org.apache.fury.resolver.NoRefResolver;
 import org.apache.fury.resolver.RefResolver;
 import org.apache.fury.resolver.SerializationContext;
@@ -101,7 +101,7 @@ public final class Fury implements BaseFury {
   private final boolean refTracking;
   private final RefResolver refResolver;
   private final ClassResolver classResolver;
-  private final EnumStringResolver enumStringResolver;
+  private final MetaStringResolver metaStringResolver;
   private final SerializationContext serializationContext;
   private final ClassLoader classLoader;
   private final JITContext jitContext;
@@ -132,7 +132,7 @@ public Fury(FuryBuilder builder, ClassLoader classLoader) {
       this.refResolver = new NoRefResolver();
     }
     jitContext = new JITContext(this);
-    enumStringResolver = new EnumStringResolver();
+    metaStringResolver = new MetaStringResolver();
     classResolver = new ClassResolver(this);
     classResolver.initialize();
     serializationContext = new SerializationContext();
@@ -325,7 +325,7 @@ private void xserializeInternal(MemoryBuffer buffer, Object obj) {
     refResolver.resetWrite();
     // fury write opaque object classname which cause later write of classname only write an id.
     classResolver.resetWrite();
-    enumStringResolver.resetWrite();
+    metaStringResolver.resetWrite();
     for (Object nativeObject : nativeObjects) {
       writeRef(buffer, nativeObject);
     }
@@ -807,7 +807,7 @@ private Object xdeserializeInternal(MemoryBuffer buffer) {
       buffer.readerIndex(readerIndex);
       refResolver.resetRead();
       classResolver.resetRead();
-      enumStringResolver.resetRead();
+      metaStringResolver.resetRead();
     }
     obj = xreadRef(buffer);
     buffer.readerIndex(endReaderIndex);
@@ -1241,7 +1241,7 @@ private void serializeToStream(OutputStream outputStream, Consumer<MemoryBuffer>
   public void reset() {
     refResolver.reset();
     classResolver.reset();
-    enumStringResolver.reset();
+    metaStringResolver.reset();
     serializationContext.reset();
     nativeObjects.clear();
     peerOutOfBandEnabled = false;
@@ -1252,7 +1252,7 @@ public void reset() {
   public void resetWrite() {
     refResolver.resetWrite();
     classResolver.resetWrite();
-    enumStringResolver.resetWrite();
+    metaStringResolver.resetWrite();
     serializationContext.reset();
     nativeObjects.clear();
     bufferCallback = null;
@@ -1262,7 +1262,7 @@ public void resetWrite() {
   public void resetRead() {
     refResolver.resetRead();
     classResolver.resetRead();
-    enumStringResolver.resetRead();
+    metaStringResolver.resetRead();
     serializationContext.reset();
     nativeObjects.clear();
     peerOutOfBandEnabled = false;
@@ -1305,8 +1305,8 @@ public ClassResolver getClassResolver() {
     return classResolver;
   }
 
-  public EnumStringResolver getEnumStringResolver() {
-    return enumStringResolver;
+  public MetaStringResolver getMetaStringResolver() {
+    return metaStringResolver;
   }
 
   public SerializationContext getSerializationContext() {

java/fury-core/src/main/java/org/apache/fury/resolver/ClassInfo.java

@@ -31,23 +31,23 @@
  */
 public class ClassInfo {
   final Class<?> cls;
-  final EnumStringBytes fullClassNameBytes;
-  final EnumStringBytes packageNameBytes;
-  final EnumStringBytes classNameBytes;
+  final MetaStringBytes fullClassNameBytes;
+  final MetaStringBytes packageNameBytes;
+  final MetaStringBytes classNameBytes;
   final boolean isDynamicGeneratedClass;
-  final EnumStringBytes typeTagBytes;
+  final MetaStringBytes typeTagBytes;
   Serializer<?> serializer;
   // use primitive to avoid boxing
   // class id must be less than Integer.MAX_VALUE/2 since we use bit 0 as class id flag.
   short classId;
 
   ClassInfo(
       Class<?> cls,
-      EnumStringBytes fullClassNameBytes,
-      EnumStringBytes packageNameBytes,
-      EnumStringBytes classNameBytes,
+      MetaStringBytes fullClassNameBytes,
+      MetaStringBytes packageNameBytes,
+      MetaStringBytes classNameBytes,
       boolean isDynamicGeneratedClass,
-      EnumStringBytes typeTagBytes,
+      MetaStringBytes typeTagBytes,
       Serializer<?> serializer,
       short classId) {
     this.cls = cls;
@@ -71,26 +71,26 @@ public class ClassInfo {
       short classId) {
     this.cls = cls;
     this.serializer = serializer;
-    EnumStringResolver enumStringResolver = classResolver.getEnumStringResolver();
+    MetaStringResolver metaStringResolver = classResolver.getMetaStringResolver();
     if (cls != null && classResolver.getFury().getLanguage() != Language.JAVA) {
-      this.fullClassNameBytes = enumStringResolver.getOrCreateEnumStringBytes(cls.getName());
+      this.fullClassNameBytes = metaStringResolver.getOrCreateMetaStringBytes(cls.getName());
     } else {
       this.fullClassNameBytes = null;
     }
     if (cls != null
         && (classId == ClassResolver.NO_CLASS_ID || classId == ClassResolver.REPLACE_STUB_ID)) {
       // REPLACE_STUB_ID for write replace class in `ClassSerializer`.
       String packageName = ReflectionUtils.getPackage(cls);
-      this.packageNameBytes = enumStringResolver.getOrCreateEnumStringBytes(packageName);
+      this.packageNameBytes = metaStringResolver.getOrCreateMetaStringBytes(packageName);
       this.classNameBytes =
-          enumStringResolver.getOrCreateEnumStringBytes(
+          metaStringResolver.getOrCreateMetaStringBytes(
               ReflectionUtils.getClassNameWithoutPackage(cls));
     } else {
       this.packageNameBytes = null;
       this.classNameBytes = null;
     }
     if (tag != null) {
-      this.typeTagBytes = enumStringResolver.getOrCreateEnumStringBytes(tag);
+      this.typeTagBytes = metaStringResolver.getOrCreateMetaStringBytes(tag);
     } else {
       this.typeTagBytes = null;
     }
@@ -118,11 +118,11 @@ public short getClassId() {
     return classId;
   }
 
-  public EnumStringBytes getPackageNameBytes() {
+  public MetaStringBytes getPackageNameBytes() {
     return packageNameBytes;
   }
 
-  public EnumStringBytes getClassNameBytes() {
+  public MetaStringBytes getClassNameBytes() {
     return classNameBytes;
   }