Objective

Some of the collision detection modules are not located in the most appropriate place, and the imports are a bit messy.

Solution

Move

• layers from collision to collision::collider
• contact_query from collision to collision::collider::parry
• feature_id from collision to collision::contact_types

I also removed the collider::* and layers::* re-exports from the collision module, and instead added a prelude for collision detection functionality.

Migration Guide

Some collision detection modules and imports have been reorganized.

The following modules have been moved:

• layers from collision to collision::collider
• contact_query from collision to collision::collider::parry
• feature_id from collision to collision::contact_types

Previously, a lot of collision detection types were also re-exported directly from the collision module. Now, there is instead a prelude for the collision module.