Adds support of NURBS weights or "rat bspline" in OBJ terms.
Tries to guess Blender knot mode better:
- Detects and closes loops. This decision is based on geometry only. No metadata is provided in OBJ for this, so importer has checkbox to disable this feature.
- Bezier knot mode allows to import circles and circular arcs.
Pull Request: https://projects.blender.org/blender/blender/pulls/131169