make code dimension agnostic

[Kwasniok]

• [x] ray segment
• [x] bounding box
• [x] bvh
• [x] hit record
• [x] entities
• • [x] triangle (non-tivial for >=4D)
• • [x] mesh (non-tivial for >=4D)
• • [x] BVH collcection
• • [x] camera (non-tivial for >=4D)
• • • [x] base
• • • [x] pinhole
• [x] textures
• [x] backgrounds
• [x] animators
• • [x] base
• • [x] triangle
• • [x] mesh
• [x] geometry
• • [x] base
• • [x] ray
• [x] scene
• [x] renderer
• [x] materials
• • [x] hit record
• • [x] scatter invocations in renderer