[Plugin Request] Airfoil Generator

Work has been done in GitHub issues, the Google Group, and Discord on airfoils. Other software packages like OpenSCAD have airfoil libraries, and it makes sense for CadQuery to have a plugin to generate common types of airfoils.

Link to a library of airfoil sections: https://github.com/winksaville/py-airfoils

No repository files, tests, or entry points are named. Start by reviewing the linked py-airfoils library and the prior discussions referenced in the issue; the work is done when the supported common airfoil types, plugin interface, and expected generated geometry are agreed and implemented.

Written by the indexing model from the issue text.