Update create_basis_compressed_glbs tool to use CgltfImporter

[aclegg3]

Motivation and Context

Updates the create_basis_compressed_glbs tool from TinyglTF to CgltfImporter

Also screens some false positives in finalize function where files in the working directory were getting picked up for rename and may not actually exist.

How Has This Been Tested

locally used the tool

Types of changes

• Docs change / refactoring / dependency upgrade
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have completed my CLA (see CONTRIBUTING)
• I have added tests to cover my changes.
• All new and existing tests passed.

[mosra]

Ah yes can't wait to replace this tower of brittle scripts with a GltfSceneConverter and maybe just

magnum-sceneconverter file.gltf file.basisified.glb \
    -c imageConverter=BasisImageConverter,imageConverter/compression_level=X

Or a scripted version in a self-contained python script. Optimistically just a week away :)