Consider supporting Blender PBR material parameters

Apparently, the Blender folks recently took the liberty to just define new, additional parameters that can appear in MTL files:
https://projects.blender.org/blender/blender/issues/101029. There is a nearly 1:1-correspondence of these parameters to the glTF PBR parameters. It could be worthwhile to look for these parameters, and provide a conversion to glTF PBR for them.

Start with the OBJ/MTL-to-glTF conversion path and compare the Blender MTL parameters described in Blender issue 101029 with the corresponding glTF PBR parameters. Done means recognized Blender PBR parameters in MTL files are converted into equivalent glTF PBR material properties.

Written by the indexing model from the issue text.