5a5f768938
Move the existing USDZ export test from C++ to Python for better validation. The resulting file is now run through the `usdchecker` system and we also check the contents of the resulting archive for the expected texture file. This helped uncover a pathing issue in the resulting archive where the 'textures' directory was misnamed on win32; though it was still functional. Pull Request: https://projects.blender.org/blender/blender/pulls/144176