Simplifies setting of physics material on prims

[Mayankm96]

Description

This PR fixes some inconsistencies in the API to apply physics materials over prims. Isaac Sim recommends using the PhysicsMaterial and GeometryPrim classes but these are not general enough to apply any physics material on any prim. The material binding API expects the prim to be physics-enabled to apply a material on it. Thus, the main contribution of the PR is to make this generic, s.t. if given a prim, one can search all prims under it and apply the physics material wherever possible. This simplifies the requirement of having geom_prim_rel_path as part of the RigidObjectCfg.

Other additions to this PR:

• A demo script to check the functionality of rigid object class with YCB objects
• Reporting an issue with using instanceable assets as markers
• Fixes The error about “Isaac-Lift-Franka-v0” task #26 , [Bug Report] Cube not interactable in “Isaac-Lift-Franka-v0” task #31

Type of change

• 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 not work as expected)
• This change requires a documentation update

Screenshots

Please attach before and after screenshots of the change if applicable.

Checklist

• I have run the pre-commit checks with ./orbit.sh --format
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• I have updated the changelog and the corresponding version in the extension's config/extension.toml file