unfollowUser method
Implementation
Future<TUIActionCallback> unfollowUser(String userId) async {
final result = await friendshipManager.unfollowUser(userIDList: [userId]);
const success = 0;
return result.code == success
? TUIActionCallback(code: TUIError.success, message: '')
: TUIActionCallback(code: TUIError.errFailed, message: result.desc);
}