Support reading of 3MF files

[HuguesDelorme]

Implement reading of 3MF files.

From @tpimh :

• https://en.wikipedia.org/wiki/3D_Manufacturing_Format
• https://docs.fileformat.com/3d/3mf/
• https://3mf.io/specification/
• https://github.com/3MFConsortium/lib3mf

[tpimh]

In my opinion, 3MF is way better documented than AMF. Since both formats try to solve the same problems, but 3MF is newer and is being developed more actively. I can't tell which format is more widely adopted.

[tpimh]

I just tested the new release, and 3MF import worked. No color support, but the geometry is rendered correctly.