--Scene Dataset default attributes filename wildcard handling.

[jturner65]

Motivation and Context

This PR adds support for a wildcard/sentinel value in the name of the render or collision asset for object attributes or stage attributes (or the navmesh, Semantic Scene asset or Semantic Scene Descriptor text file for stages) in the "default_attributes" tag of the Scene Dataset configuration file. This value, "%%CONFIG_NAME_AS_ASSET_FILENAME%%" will be replaced by the name used to synthesize the attributes upon instantiation, so a stage- or object-specific value can be requested at the Scene Dataset level, in one spot. Any value synthesized using this tag will be verified to actually exist before it is written (otherwise the field is cleared).

With datasets like HM3D, where the data is organized such that a scene's assets and other pertinent information is stored in a single directory specific to that scene, this enables fairly complex handling of subordinate assets without individual per-scene stage configurations.

All c++ and python tests pass. Verified to work with Appen POC HM3D scene annotations.

How Has This Been Tested

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.

[Skylion007]

Looks good to me. Also good job on making all the std::functions a const ref since they aren't trivially copyable.