CharacterValidateNickname
Callable
Parameters
C: Character
The character to change the nickname of.
Nick: string
The name to use as the new nickname. An empty string uses the character's real name.
fromOwner: boolean = false
Returns NicknameTooLong | NicknameInvalidChars | NicknameLocked
null if the nickname was valid, or an explanation for why the nickname was rejected.
Validate the given character's nickname