Link the communication between individual game rooms and the main lobby

It should be possible to take a look at the main lobby from within the game setup room by clicking to it without having to leave the bracket (as host or game participant). For example, this could be used to promote the own game, to find/invite another player (who is not already on your friendlist) in suitable strength based on their player profile, or to check how crowded the lobby is to determine whether it's worth the wait.