fix/3d-boundary-layers

Recent merge of feature/mesh_spacing broke a number of parts of the mesh generation, mostly do with orientation.

The CAD orientation routines have now been rewritten in this branch and the relevant code updated.

3 more regression tests, which didnt work prior to this fix, have been added

A small amount of wall time optimisation has been done to the OCC cad interface and the reduction of some L0 asserts to L1.