Respect PointBehaviour for tiglWingGetSegmentEtaXsi

[rainman110]

Description

I had to change the class structure / method signature slightly
to allow to pass, how GetEtaXsi is evaluated.

Unfortunately, GetEtaXsi on the paramter surfaces is almost
a factor of thousand slower, which could be a problem for the
VTK export with metadata. Therefore I decided to use the old
eta / xsi interpretation for the exports for now.

closes #808

How Has This Been Tested?

To validate, I changed the consistency test, added a performance
test and added a function to tiglviewer to play around with
the function.

Screenshots, that help to understand the changes(if applicable):

Checklist:

• A test for the new functionality was added.
• 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.

[codecov-commenter]

Codecov Report

Merging #811 (1833e84) into master (e05dfb1) will increase coverage by 0.41%.
The diff coverage is 89.36%.

@@            Coverage Diff             @@
##           master     #811      +/-   ##
==========================================
+ Coverage   62.17%   62.58%   +0.41%     
==========================================
  Files         291      291              
  Lines       23438    25628    +2190     
==========================================
+ Hits        14572    16039    +1467     
- Misses       8866     9589     +723     

Impacted Files	Coverage Δ
src/wing/CCPACSWing.h	100.00% <ø> (ø)
src/wing/CCPACSWingSegment.h	50.00% <ø> (ø)
src/wing/CCPACSWing.cpp	74.06% <66.66%> (+0.51%)	⬆️
src/wing/CCPACSWingSegment.cpp	85.59% <94.28%> (+4.60%)	⬆️
src/api/tigl.cpp	57.06% <100.00%> (+2.64%)	⬆️
src/geometry/CTiglTriangularizer.cpp	87.69% <100.00%> (+0.86%)	⬆️
src/wing/CCPACSWingComponentSegment.cpp	51.89% <100.00%> (+1.61%)	⬆️
... and 2 more