v1.0.8

v1.0.8
fbx:
- fix embedded image export
- improved metallic workflow
- fix camera import orientation
gltf:
- export fix - token2channel default rgb tokens to use r channel
- export alphablendmodetest test asset without causing missing texture error
- propagate one animation track through import/export
- anisotropy import and export
ply:
- fix gsplat bounding box for framing into the asset
utility:
- Write a USDRenderSettings prim in the Sdf layer & do not finalize the layer in writeLayer()