Blender Git Loki

Geometry Nodes: Add initial scattering nodes

The first is a "Point Distribute" node, which takes a mesh and outputs a
pointcloud, scattering points randomly on the surface based on the input
density. The distribution algorithm is extremely basic at this point, and
doesn't take into account an attribute weight at each vertex.

The second node is a "Point Instance" node, which is mainly a placeholder
until the engineering design for how to work with instancing in geometry
nodes is decided. For now it just runs the same code that the convert
pointcloud to mesh operator uses.