Improve netplay setup dialog UX

* Focus "Hash Code" / "IP address" text box by default in "Connect"
* Focus game list in "Host" tab
* RETURN keypress now host/join depending on selected tab
* Remember last hosted game
* Remove PanicAlertT:
	* Simply log message to netplay window
	* Remove them when they are useless
* Show some netplay message in OSD
	* Chat messages
	* Pad buffer changes
	* Desync alerts
* Stop the game consistently when another player disconnects / crashes
* Prettify chat textbox
* Log netplay ping to OSD

Join scenario:
* Copy netplay code
* Open netplay
* Paste code
* Press enter

Host scenario:
* Open netplay
* Go to host tab
* Press enter

Source/Core/VideoCommon/VideoConfig.h

@@ -82,6 +82,8 @@ struct VideoConfig final
 
   // Information
   bool bShowFPS;
+  bool bShowNetPlayPing;
+  bool bShowNetPlayMessages;
   bool bOverlayStats;
   bool bOverlayProjStats;
   bool bTexFmtOverlayEnable;