Add in-game Chat

[aashutoshrathi]

Description

This was requested by more and more users, and they should be able to chat alongside the game just as lichess and chess.com allow it. It can be a separate service/micro-rollup that keeps the chats along with the Game ID.

The goal is for users to be able to send msgs from their wallet to another user, in real time for a game.

This will require changes on front end as well as a new micro-rollup/service.

If this is chosen to be done on auxiliary Micro-rollup an optimized State needs to be proposed for this. To keep the state bloat minimum but still be able to verify the chats for a game.