Refactor CFuseShapes for more robustness

[joergbrech]

The class CFuseShapes is used to fuse named shapes in TiGL. The implementation is a workaround to performance and robustness issues with an old OCCT version. Since we switched to OCC 7.4, we can profit from the newer more robust fusing algos from OCCT. We should replace the implementation of CFuseShapes to use the OCCT native algorithms again.

Currently, the ducts are fused to a single cutting tool using the OCCT fuser rather than TiGL's CFuseShapes (see PR #889):

https://github.com/DLR-SC/tigl/blob/37def5e7eaee8acc5f8904600630d10ea62c54bf/src/ducts/CCPACSDucts.cpp#L84-L105

After we move this logic to CFuseShapes, we should also adapt the CCPACSDucts code to use the adapted CFuseShapes again.

When migrating the algorithm, we must make sure that the face traits are kept in tact.