Add extra couple of options to game settings

The launcher is missing a couple of settings for 5.x games that it'd be good it could set. One is new, the "Mute game audio if in the background" one, and the other is one that's in the old WWSetup and is now also ingame, the "Skip Quit Confirmation" option. They're both set in the registry, like the volumes, so shouldn't be too tricky to add, I'd think?