Add system app to browse/view/delete screenshots

[R0M4N0F5K7]

Definitely a new feature, but it's amazing to me that the original OS comes without it...

[raewtf]

scratch and I have started talkin' about doing something like this, except as its own bespoke app rather than an index feature (i believe we can get away with it being able to run without needing an installer or anything like that, so it makes sense to make it as immediately accessible as possible instead of bundling it in with this launcher, at least imo). it might be a little while before there's anything to show (if at all), but we'll probably make a devlog in the Squad discord at some point about it