Add helper function for creating midsurface (a.k.a VLM) meshes

[A-CGray]

Purpose

Adds a helper function that uses a very similar approach to the fitted FFD generation code to generate a midsurface mesh of a wing, that can then be used in a VLM code. The generated meshes follow the camber line of each section of the wing, for example:

I added a test that uses a new input file that I guess I need to upload somewhere?

Expected time until merged

No rush

Type of change

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (non-backwards-compatible fix or feature)
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no API changes)
• Documentation update
• Maintenance update
• Other (please describe)

Testing

Checklist

• I have run flake8 and black to make sure the Python code adheres to PEP-8 and is consistently formatted
• I have formatted the Fortran code with fprettify or C/C++ code with clang-format as applicable
• I have run unit and regression tests which pass locally with my changes
• I have added new tests that prove my fix is effective or that my feature works
• I have added necessary documentation