Consistent implementation for combining fuselage guide curves and kinks

[svengoldberg]

Currently, the definition of (starting and end points of) fuselage guide curves is not consistent to user-defined parameterization for (e.g.) kinks. Those guide curve points are, up to now, defined based on the arc length of the start profile and end profile, respectively. While the user-defined parameterization can arbitrary differ from that (see issue #745).

This PR introduces the new CPACS nodes fromParameter and toParameter to account for this 'problem' to make it easier for users to sync guide curves with kinks. The node is implemented via a choice element and the old implementation is kept as the default case to not get in the way with existing code, CPACS files and tests. Since the CPACS scheme is changed, it has to be thought about a CPACS PR, as well.

TODO:

• [ ] Implement meaningful tests
• [x] Think about cases when the parameterization is not in the range of [0,1]
• [ ] Take care about wings
• [ ] (Potentially clean up the changed code)

Fix issue #745

Checklist:

• [ ] A test for the new functionality was added.
• [X] All tests run without failure.
• [ ] The new code complies with the TiGL style guide.
• [ ] New classes have been added to the Python interface.
• [ ] API changes were documented properly in tigl.h.