Add support of build123d

[kcleung]

build123d is a python and opencascade based code-cad system that is an evolution of cadquery (which is already supported in cadhub), but has a less restrictive API:

https://build123d.readthedocs.io/en/latest/index.html

It also has several parametric parts libraries

Would be great if cadhub can extend support to build123d too.

[KarthikDani]

Yes, I was recently trying out Code CADs, I decided using Build123D over CadQuery. Kindly add the support

[fangpenlin]

@kcleung @KarthikDani there's https://MakerRepo.com for build123d specifically (disclosure, I built MakerRepo). it's not open sourced like this project, but most of the workflow is open-sourced and the cli tool which can run most of the workflow is open-sourced https://github.com/LaunchPlatform/makerrepo-cli