Python Module: Bundle VFX library python bindings

When calling bpy.utils.expose_bundled_modules(), these modules are
added to sys.path.

This provides a solution/workaround to two problems:
* Using bpy together with packages like usd-core is problematic. Besides
  crashing due to C++ symbol conflicts, it's just impossible to import
  different versions of the same module, or to have distinct environment
  variables for both. (#127132)
* Blender add-ons using these VFX modules do not currently work with
  the bpy module.

This adds about 15MB to the bpy package.

Pull Request: https://projects.blender.org/blender/blender/pulls/133082

tests/blender_as_python_module/import_bpy.py

@@ -8,3 +8,12 @@ sys.path.append(sys.argv[1])
 
 # Just import bpy and see if there are any dynamic loader errors.
 import bpy
+
+# Try bundled libraries
+bpy.utils.expose_bundled_modules()
+
+from pxr import Usd
+import MaterialX
+import OpenImageIO
+import PyOpenColorIO
+import pyopenvdb