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.
These were being serialized as the base type. On deserialization, due to
the HitWindow of objects being non-null, they would not get correctly
initialised by the CreateHitWindows() virtual method.
- Closes#10403