Root of the issue is that `BKE_object_eval_boundbox` (that ports back
evaluated bbox to orig object during active depsgraph evaluation) is
only called when object's geometry actually is evaluated.
However, with new undo, often Object itself can be changed by undo,
without requiring its geometry to be re-evaluated, which was leading to
the evaluated bbox not being copied back into orig object anymore.
Fixing that by moving bbox copying-to-orig code into
`BKE_object_sync_to_original` instead, which is always executed when
object is evaluated (as hinted by the comment above
`BKE_object_eval_boundbox` actually).
Also allows to cleanup code for armature eval, apparently.
Maniphest Tasks: T83422
Differential Revision: https://developer.blender.org/D9789
2a8b987e9e