Add separate chat panel for spectators and players

Forces the chat and performance panels to be re-initialized when a
player transitions to spectators. This ensures that spectators don't
get to see faction themed widgets.

OpenRA.Mods.Common/Widgets/Logic/Ingame/LoadIngamePlayerOrObserverUILogic.cs

@@ -54,7 +54,6 @@ namespace OpenRA.Mods.Common.Widgets.Logic
 			}
 
 			Game.LoadWidget(world, "DEBUG_WIDGETS", worldRoot, new WidgetArgs());
-			Game.LoadWidget(world, "CHAT_PANEL", worldRoot, new WidgetArgs() { { "isMenuChat", false } });
 
 			world.GameOver += () =>
 			{