Fixes for compatibility with upcoming usd-0.19.01 release

[pmolodo]

Description (this won't be part of the changelog)

Just a branch / pr to places fixed needed to build against the latest dev branch (19.01)

Changelog

Fixed

• GetRendererPluginDesc changed to GetRendererDisplayName (usd 19.01 fixes)

Checklist (Please do not remove this line)

• [X] Make sure the Title and Description of the PR make sense and provide sufficient context for your work
• [X] Do any added files have the correct AL Apache Licence Header?
• [X] Are there Doxygen comments in the headers?
• [X] Are any new features, behaviour changes documented in the .md format documentation?
• [X] Have you added, updated tests to cover new features and behaviour changes?
• [X] Have you filled out at least one changelog entry?

[pmolodo]

Closing in favor of: https://github.com/AnimalLogic/AL_USDMaya/pull/133