GLTF Mesh Import: Option to automatically apply materials to mesh

[AtlasLinden]

Add the ability to or an option upon upload to automatically apply materials to a mesh.
For a large mesh with many materials, it is unfeasible for a user to apply each material one by one.

Test Plan

This model includes 167 separate materials: https://raw.githubusercontent.com/KhronosGroup/glTF-Sample-Assets/main/Models/VirtualCity/glTF-Binary/VirtualCity.glb
Verify that the materials apply automatically either upon upload or via a separate option depending on feature design.

[aiaustin]

Also allow a way to use previously uploaded materials that exist in inventory, to support update of mesh models without creating duplicates of any materials. Maybe by nominating a folder containing the materials to use if some means to partial match on material name or content deduplication can be done.