CLI: add game-screen parameter, save last game window screen in no-gui mode

[Megamouse]

• Adds the CLI argument "game-screen" which can be used to set a preferred screen for the game window. Use it for example like: rpcs3.exe --no-gui --game-screen=1
• Saves the last game window screen and re-uses it in the no-gui mode if no game-screen is set
• Moves the global parameter for the fullscreen mode to member variables of gui_application and gs_frame

fixes #12828