[Go] Support convert utf16 encoded string to utf8 string about incubator-fury

[LiangliangSui]

Hi @chaokunyang , Have you started implementing this feature? If it hasn't been implemented yet, I can take over and implement this.

[chaokunyang]

@LiangliangSui I haven't, feel free to take over it

[LiangliangSui]

Okay, I will do this.

[LiangliangSui]

@chaokunyang We currently use UTF8 for cross-language serialization, and only Java(not cross-language) uses Latin/UTF16.

  public void writeString(MemoryBuffer buffer, String value) {
    if (isJava) {
      writeJavaString(buffer, value);
    } else {
      writeUTF8String(buffer, value);
    }
  }

Will we use UTF16 as the default cross-language String encoding in the future?

I see that the cross-language currently designed in fury_xlang_serialization_spec still uses UTF8 as the default.

[chaokunyang]

Depends on the language and the string. For golang, since the string is utf-8 encoded already. Fury go will encode data as utf8 string by a copy. But java/javascript/python may encode string as latin1 or utf16 and send to furygo. So we need to support utf16 too. And if the peer language, we may configure furygo use latin1/utf16 by default too.

[LiangliangSui]

But java/javascript/python may encode string as latin1 or utf16 and send to furygo.

Latin1/UTF16 is only used in Language.JAVA and will not be sent to furygo.

[LiangliangSui]

Okay, I got it.

[chaokunyang]

In the future, java/javascript/python may all encode string as latin1/utf16 and send to furygo.