Fix formations reshaping incorrectly & related issues.
Formation were reshaping in cases where they should not (such as when the controller is waiting on members).
This made them look very odd for some orders.
This also cleans up held positions for formations somewhat.
Also:
- rP23346 fixed units not facing correctly after a formation-walk. The fix is correct, but we can actually make it slightly more self-contained by moving everything in leave. Also clarify comments.
- This fixes some very broken code in rP22447 in FORMATIONMEMBER.WALKING.MovementUpdate. It never errored because formation controllers weren't moved out of the world before.
Reviewed By: Angen
Fixes #5443
Differential Revision: https://code.wildfiregames.com/D2763