Add collision priority property to TileSet physics layers

[KeyboardDanni]

Fixes #98772.

This adds a collision_priority property to TileSet physics layers. This allows you to make the resulting collision bodies produced by the TileMap have a higher collision priority (for example, 96.0), meaning the depenetration phase is much less likely to move an object into a wall if it's inside another object that suddenly becomes solid.

Demo of before and after:
TilesetCollisionPriorityDemo.zip

[KeyboardDanni]

Video:

TilemapCollisionPriority.mp4

[rburing]

This looks fine from the physics perspective. The typical use case is increasing collision priority on a floor or a wall, and most likely you want to do this for all floors and all walls (of a given type), so it makes sense to have this property on the TileSet level.

[Repiteo]

Thanks!