Fix reversed assertEquals parameter order in Long modification tests (#237)

Fixed incorrect parameter order in assertEquals calls where the actual value
was placed before the expected value. The JUnit convention expects the
expected value as the first parameter.

Added 'L' suffix to numeric literals to ensure proper Long type matching.

Related to tls-attacker/TLS-Attacker-Development#1321

Author: ic0ns

src/test/java/de/rub/nds/modifiablevariable/mlong/LongAddModificationTest.java

@@ -87,7 +87,7 @@ void testToString() {
     void testConstructors() {
         LongAddModification constructor = new LongAddModification(5L);
         assertNotNull(constructor);
-        assertEquals(constructor.getSummand(), 5);
+        assertEquals(5L, constructor.getSummand());
 
         // Test copy constructor
         LongAddModification copy = new LongAddModification(modification);

src/test/java/de/rub/nds/modifiablevariable/mlong/LongExplicitValueModificationTest.java

@@ -91,7 +91,7 @@ void testConstructors() {
         // Test default constructor
         LongExplicitValueModification constructor = new LongExplicitValueModification(5L);
         assertNotNull(constructor);
-        assertEquals(constructor.getExplicitValue(), 5);
+        assertEquals(5L, constructor.getExplicitValue());
 
         // Test copy constructor
         LongExplicitValueModification copy = new LongExplicitValueModification(modification);