Show game background during controller/keyboard game selection

There's no useful way to do it for touch/click, but I think this is nicer when using a controller.

Also, prevents UI locks when the disk is slow (e.g. spinning up) reading iso data, reads PIC0 from PBPs (several PBPs indeed had PIC0 there.)

I actually think playing SND0 might be nice (#2585), but I'm not interested enough to do it.  But I did at least add a flag to grab SND0 if anyone wants to.

-[Unknown]