Multiplayer Server Pause

1.2.0 (untested backport from MC 1.20.2):

• Fixed being kicked from integrated servers with an invalid message error when the integrated server shuts down.
• Fixed being unable to connect to integrated servers if the integrated server was paused.
• Fixed dedicated servers showing at least 1 player connected on the server when is set to pause with no players connected/last player disconnected.
• (Fabric only) Fixed remote clients randomly being kicked when the server's pause state is switched.
• Added config to send a chat message when a player toggles their pause state.
• Added some French localisation contributed by Calvineries (thank you!)
• Updated internal mixin names to match mixin conventions.