Support for HDRP and URP default materials.

[vidurvij-apptronik]

Is your feature request related to a problem? Please describe.
I am using the HDRP pipeline with MuJoCo. It seems like the default material is Standard which is not rendered properly in HDRP. I am adding a feature to detect the pipeline being used in the Unity project and add change the default material generated for MuJoCo.

Describe the solution you'd like
I have already created the solution.
#1345

[justin-foehner]

Hello, I'm currently running into the same issue. It looks like the pull request at #1345 is still pending, but otherwise looks ready to merge.