Create: Coasters Simulated Additions

- Support Rivet — locks a sublevel like a normal rivet, but stays invisible with no hitbox until you hold the item. Yellow, slightly see-through.
- Support Block — same visibility rules as a support rivet, but a normal full cube that does not create a sublevel.
- Cart Support Tool — place a floating support rivet on a coaster cart. Shift-right-click opens a 3D editor of the whole cart. Alt-right-click copies the settings onto the tool. Right-click pastes them onto another cart (places a rivet if it does not have one yet).
- Track Override — hold in the offhand with coaster track or a wrench in the main hand to skip track placement and edit limits.
- Potential fix for Rivits breaking on Sublevels