--[BE/Bugfix]Modify creation of Articulated Object from URDF file name.

[jturner65]

All AO creation is driven by ArticulatedObjectAttributes now, with the caveat that to be used, any ArticulatedObjectAttributes must reference an existing and legitimate URDF file by relative path name from which to actually build the AO. ArticulatedObjectAttributes can be created using the name of their corresponding URDF file, in which case they will reference -that- URDF, and there is no need to complain if there is no existing ArticulatedObjectAttributes matching that name, since a legal one will be created . This PR removes the erroneous and potentially misleading complaint, and proceeds silently to make a new ArticulatedObjectAttributes referencing the passed URDF file if one does not already exist.

This was peeled off this PR, to minimize topical divergence.

Motivation and Context

How Has This Been Tested

All C++ and python tests pass (it's just a message change)

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]

Thanks!