Closes #13443.
Closes https://github.com/ppy/osu/issues/12630.
EditorBeatmap.Update
PerformOnSelection
TernaryStateMenuItem
OsuSelectionHandler
Add a HitObjectUsageEventBuffer to handle HOC events appropriately
TransferBlueprintFor
Rename hitobject blueprints and tie them to HitObjects
Co-authored-by: Bartłomiej Dach <dach.bartlomiej@gmail.com>
Add skin editor saving / loading support
Add rotation controls to editor selection box corners
SelectionHandler
GetStateFromSelection