There were cases in the editor where rewinding of transforms would
leave the `DrawableHitObject` in a non-`IsPresent` state, resulting in
this scheduled logic never running.
This would in turn cause ghost hitobjects, which disappear under certain
circumstances.
Reproduction:
- Open editor to empty beatmap
- Place single hitcircle at current point in time
- Drag editor timeline backwards to seek before zero, and wait for
return to zero
- Select hitcircle in playfield
- Drag hitcircle to right in timeline, triggering a start time change
Until now UpdateStateTransforms was applying results offsets to
StartTime. This didn't cover the case of a HitObject with duration,
where the call would be made with `StartTime + hitOffset` rather than
`EndTime + hitOffset`.
To resolve this, a new method has been added which should be used to
handle hit-specific state transforms.