Pattern Selector Rebuilt

I rebuilt the menu that let you select a garbage pattern in 2-player mode! I tried to give some visual cues similar to the main menu so it'd be easy to figure out.

There's some more mouse support throughout the menus, but it's still limited: if you start up a game with players that don't have inputs mapped, you'll soft-lock. The pattern selector has mouse support, and you can now click the "Ready!" in the main menu to start a game. The feature is only for debugging, but it could help quickly set up some configurations in a pinch.