improve start zone creation re: tp dest

[PeenScreeker]

What feature is your improvement idea related to?

Auto-pick tp dest for a track/stage start if it's within the region volume

Describe the solution you'd like

when ending point placement for a region of a start zone, look through suitable entities and pick one that is inside the region volume (if it exists).

Describe alternatives you've considered, if any.

• button to pick nearest tp dest to region centroid
• sort tp dest list by distance from region centroid

Additional context

No response