Basic geometry module

For most simple example projects it would be pretty useful to just render simplified geometry like cubes, spheres, cylinders or teapots. However this shouldn't require the asset-loader module all the time because creating a .gltf-file for something like this is total overkill.

That's why I suggest to develop a geometry module which can instance different kinds of basic geometry as meshes. This could also include generating signed distance fields for those geometric bodies and calculating intersection tests.