STEP/GLB/BREP/XAO 3D model export improvements
Changes:
- Option to export pads separately from tracks+vias
- Options export silkscreen and soldermask as flat faces
- Improve 3D model export dialog layout
- Use VisMaterialTool to specify metallic-roughness for glTF.
- Less OCCT boolean operations (faster, less bugs)
Fixes #2072 (closed), Partially addresses #17402