Use ColliderTrees for spatial queries

[Jondolf]

Objective

Fixes #403.

#927 added ColliderTrees for the new BVH broad phase. We should reuse them for spatial queries instead of maintaining and using a separate BVH from Parry.

Solution

In short:

• Add more traversal methods on Bvh2 via extension traits (we should probably upstream these)
  • sweep_traverse, sweep_traverse_miss, sweep_traverse_anyhit, and sweep_traverse_dynamic
  • squared_distance_traverse and squared_distance_traverse_dynamic
• Add methods for BVH traversal on ColliderTree
  • ray_traverse_closest and ray_traverse_all
  • sweep_traverse_closest and sweep_traverse_all
  • squared_distance_traverse_closest
  • point_traverse
  • aabb_traverse
• Remove SpatialQueryPipeline, and use the ColliderTrees traversal methods for SpatialQuery

This involved some other miscellaneous changes:

• Shape casts now returns hits in arbitrary order when max_hits > 1, similar to ray casts.
• point2 and normal2 were previously in local space, despite what the docs state. They are now in world space.

Testing

Tested different spatial queries in examples.

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Showcase

Before, updating the spatial query pipeline was extremely expensive for large scenes with a lot of colliders:

(note that the tree optimization cost is partially hidden here, as it is run in parallel with the spatial query pipeline update)

Now, using the much more optimized ColliderTrees, that overhead is gone:

Future Work

• Generic collider types for spatial queries (Draft: Make spatial queries generic over colliders #810)