Could lead to crashes after reversing a note cluster and playing it
back.
The root cause of the crash was that the hotkey operations were not ran
inside of an editor change handler operation. This, in turn, caused the
autoplay replay to not be regenerated after flipping an object cluster,
therefore finally manifesting as a hard crash due to negative time
offsets appearing in judgement results, which interfered with the
default implementation of note lock.
Note that this incidentally also fixes the fact that selection box
hotkey operations (reverse and flip) did not handle undo/redo.
2e63c2ce20