--[BE] - Miscellaneous minor refactors and cleanup

[jturner65]

Motivation and Context

This PR will contain various minor refactors and cleanup that I find as I complete other BE work that may be thematically orthogonal to the purpose of that work.

An important issue this PR addresses is that the python tests will currently abort if Habitat-sim is compiled with audio support. This is due to the import of habitat_sim in conftest.py causing an invalid free() unless the python quaternion library is imported first. This is discussed in this issue. Until a reason for this aberrant behavior can be determined, quaternion will be imported here so tests and examples don't fail.

NOTE : There is still an ongoing issue with running python tests with the audio subsystem enabled during compilation, where a greedy path without any action noise is perceived somehow as being a PyCapsule object; addressing that is beyond the scope of this PR.

How Has This Been Tested

locally c++ and python tests

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.

[aclegg3]

Yuck, but thanks for patching it and I appreciate the comments for future BE clarity. 👍