Expose ArticulatedObject creation_attributes

[aclegg3]

Motivation and Context

Follow-up refactor after adding support for ArticulatedObjectAttributes to expose creation attributes for AOs.

How Has This Been Tested

TODO

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.

[jturner65]

LGTM
I posted a suggested change to slack (easier to specify there than here, since it involved a couple other files) but it isn't essential, although it would be nice. Your call.

[jturner65]

LGTM! Thanks!