Clean-up CPP

[jzwar]

Overview

Much of the unused, unmaintained code in bezman was stripped from the base, core functions were moved to splinepy.

Addressed issues

• Cluttered code
• Get rid of all warnings during the build
• Faster execution by avoiding copies of points in interfaces

Checklists

• [x] Documentations are up-to-date.
• [ ] Added example(s)
• [ ] Added test(s)

[jzwar]

Couple of unresolved issues open for discussion:

• [x] Currently online tests fail, because uffpy is locally imported (will be resolved, once either uff or funi are added as dependencies)
• [x] py_interfaces.hpp is not initialized as it is directly used by py_multi_patch. Do we want to bind it and determine interfaces from python side? Where to place the file to keep the structure consistent?
• [x] MFEM is stripped of the edges-group. Is this temporary or can it stay like this?

Let's talk about it in person @j042

[jzwar]

Maybe another option would be to integrate the uff routine (now that it works) into funi? I just don't want to let the project die.

[jzwar]

This PR is on hold till all these PR are merged:

• [x] uff
• [x] BSplineLib
• [x] bezman