One at a time for now

Still pretty fucked, and pending fix osu-side

Will need to make use of future additions to the editor osu-side to make this work better.

It makes the SlideSelectionHighlight visually more consistent with the selection highlights of other HitObjects, and more importantly allows us to avoid making something similar for SlideFans.

Improved visuals, highlighting the current part more.
Added validity checking to paths, preventing certain types of slides that are too fucked up

Was I drunk at the time???

It didn't need to be explicitly set to be re-evaluated, since the currentLaneOffset being different will guarantee a re-evaluation.

Temporary measure for now, should be fixed game-side

This allows slides to be placed end to start

Some node sample shenanigans

This allows nested objects to inherit parents' SampleControlPoint, since they don't get one when created via the editor due to the control point being non-legacy.

Further reading: ppy/osu#15618

It was in fact, not empty

The bodies of the slide will maintain proportions when adjusting duration using the timeline

It could intrude on the user who is using the slide toolbox