[FEATURE] Distance queries for the primitives (distance to surface)

**Is your feature request related to a problem? Please describe.**
Provide an interface to query the (closest-) distance to the surface from any point in space in or surrounding the scene, preferable using the already existing acceleration structures. This kind of query is useful in many applications involving inhomogeneous materials.

**Describe a possible solution.**
Implement a distance to surface function for each primitive. Implement a distance traversal for the bvh (check if point is inside bounding box of node).

**Describe alternatives you've considered**
Using a library that provides the acceleration structured and queries for the primitives.

**Additional context**
The query would be available in the scene api and provide the prim_id, geom_id, closest_point and closest_distance.