Blender Git Loki

deps: Update lib names for USD on windows

USD: Library upgrade 19.11 ? 20.02

This requires a few changes:
- Some parts of our patch are no longer necessary, as the USD library
now includes those changes.
- The rest of the patch needed adjustment as the `pxr/base/lib/*`
directories in USD's source code have moved to `pxr/base/*`.
- The new Material Binding API is used when exporting meshes.

Note that this does not enable the USD Python API for inclusion in
Blender. It just aims at being an as-simple-as-possible version upgrade
of the USD library.