caracter by character.
Features:
* FastStringBuilder:
    + ReplaceOne: replace an oldChar with a newChar and break after
    + ReplaceOne: replace an oldChar with a newChar, starts from specific index and break after
    + get_str: get the string formated char of that index.
* GlyphFixer:
    + Fix_Taged: fix the taged string with the original string shape
    + FixLa: its a specific type, لا , there is two version, one with hex code: 0xFEFC and 0xFEFB and other version is \0xFE8E\0xFEE0.
      the first version because it is one character it will break the taging. this function will replace them with the second version.
* RTLSupport:
    + FixRTL:  add another FixRTL function with the Fix_Taged suppurt. the original function will work just fine.
* RTLTextMeshPro/RTLTextMeshPro3D:
    + add_tag: add a tag to the string at the index.
    + UpdateText/GetFixedText: modified this functions to enable the fixing taged string process.
* RichTextFixer:
    + GetUntaged: get the untaged version of the string.
* TextUtils:
    + IsGlyphFixedArabicCharacter: implement support for Special La characters.