INIT clean up and Clipper2 integration

[petrasvestartas]

Added

• Added Clipper2 to CMakeLists.txt

Changed

• Mapping method crops the pattern mesh to the boundaries of the target mesh.

Removed

• Removed all the modules from init.py

[tomvanmele]

LGTM although i think the mapping loop looks a bit weird

builds not passing

[petrasvestartas]

The output of the mesh map function is a list of points and faces representing individual polygons:

mv, mf = map_mesh((v, f), (pv, pf), clip_boundaries=True)
mesh_mapped = Mesh.from_vertices_and_faces(mv, mf)

This means, that duplicates points have to be removed.
This can be done in COMPAS:

mesh = Mesh.from_polygons(mesh_mapped.to_polygons())
mesh.weld()

Otherwise, if duplicate points are removed in libigl in the cropping method, mapping should be faster too.

UPDATE:

below hash method is implemented to remove duplicate points within a tolerance.

[jf---]

very cool the clipper2 integration!