Various pin sync improvements

[Toastbrot236]

After some thinking and watching feedback from some people, I've decided to come up with this list of changes we should do to how we handle syncing pins:

• Replace IsBeta with just a game attribute in PinProgessRelations. IsBeta was used so retail builds and beta builds would share their pin progresses, but with the introduction of Platform to the primary key, this is now only useful to share progress between lbp2/3 on ps3. This is useless, because the user can just transfer their progress themselves by importing their save anyway. Also it'd be more fun to track lbp2/3 progress separately probably.
• There should be a way to disable pin syncs (or atleast just that of non-server-sided pins, since people get confused when they suddenly unlock client-side pins, like story pins, on new saves).
• There should also be a way for a user to nuke their own progress on either a certain pin, or all pins of a game + platform.

I might add more to this list later.