[FEATURE] Group Reject Chat Code

[ernesernesto]

If an user kicked from a group, they will get a message with Chat code 6 kicked from group according to https://heroiclabs.com/docs/social-realtime-chat/

But user applying to a closed group, and then rejected with GroupUsersKick would never got any rejection code since nakama currently doesn't have any. Can we have something on the ChatCode e.g ChatCode 10 to inform rejected users that his application to a particular group is rejected? Also with the group Id in the message content so user on the client side can show what guild the rejection comes from.

This could be done easily on AfterKickGroupUsers but a built-in functionalities on nakama would be helpful

Thanks!