[FileUpload] Allow special characters in file names (#217361)

## Summary

This PR adds the ability for file names to have special characters.
Closes: #210312

Author: kowalczyk-krzysztof

src/platform/packages/shared/shared-ux/file/file_upload/impl/src/util/parse_file_name.test.ts

@@ -18,13 +18,13 @@ describe('parseFileName', () => {
 
   test('  Something_*  really -=- strange.abc.wav', () => {
     expect(parseFileName('  Something_*  really -=- strange.abc.wav')).toEqual({
-      name: 'Something__  really ___ strange_abc',
+      name: 'Something_*  really -=- strange.abc',
     });
   });
 
   test('!@#$%^&*()', () => {
     expect(parseFileName('!@#$%^&*()')).toEqual({
-      name: '__________',
+      name: '!@#$%^&*()',
     });
   });
 

src/platform/packages/shared/shared-ux/file/file_upload/impl/src/util/parse_file_name.ts

@@ -14,9 +14,6 @@ interface Result {
 export function parseFileName(fileName: string): Result {
   const withoutExt = fileName.substring(0, fileName.lastIndexOf('.')) || fileName;
   return {
-    name: withoutExt
-      .trim()
-      .slice(0, 256)
-      .replace(/[^a-z0-9\s]/gi, '_'), // replace invalid chars
+    name: withoutExt.trim().slice(0, 256),
   };
 }

src/platform/plugins/shared/files/server/routes/common_schemas.ts

@@ -9,38 +9,20 @@
 
 import { schema, Type } from '@kbn/config-schema';
 
-const ALPHA_NUMERIC_WITH_SPACES_REGEX = /^[a-z0-9\s_]+$/i;
-const ALPHA_NUMERIC_WITH_SPACES_EXT_REGEX = /^[a-z0-9\s\._]+$/i;
-
-function alphanumericValidation(v: string) {
-  return ALPHA_NUMERIC_WITH_SPACES_REGEX.test(v)
-    ? undefined
-    : 'Only alphanumeric characters are allowed as file names';
-}
-
-function alphanumericWithExtValidation(v: string) {
-  return ALPHA_NUMERIC_WITH_SPACES_EXT_REGEX.test(v)
-    ? undefined
-    : 'Only alphanumeric characters, spaces (" "), dots (".") and underscores ("_") are allowed';
-}
-
 export const fileName = schema.string({
   minLength: 1,
   maxLength: 256,
-  validate: alphanumericValidation,
 });
 
 export const fileNameWithExt = schema.string({
   minLength: 1,
   maxLength: 256,
-  validate: alphanumericWithExtValidation,
 });
 
 export const fileAlt = schema.maybe(
   schema.string({
     minLength: 1,
     maxLength: 256,
-    validate: alphanumericValidation,
   })
 );