Add optional "no in game chat" feature

[Belonit]

CnCNet/yr-patches#7

About
Some players are often trolled within in-game chat, mostly commoly in ranked matches. (Quickmatch)

As a player, I want to:

• Have the ability to disable the chat entirely so no chat is received from any player.
• To be notified in game when attempting to chat with it disabled, e.g. "You currently have in-game chat disabled".

Task detail:
Disabling in-game chat should be handled by the client. Spawner should read from RA2MD.ini