Port the Python VSM v2.3.0 tests for features Julia already has #417

Port the Python VSM v2.3.0 tests for features Julia already has
Python (awegroup/Vortex-Step-Method, tag v2.3.0) has tests whose property no Julia test pins, although the feature exists in Julia. Read both sides before porting: a matching name is not evidence. Found by reading only, so some may turn out covered.

tests/Filament/test_SemiInfiniteFilament.py: test_point_far_from_filament, test_uinf_effect.
tests/Panel/test_Panel.py: test_lei_airfoil_breukels_polynomial_new_against_old (a panel between two different Breukels sections gets the average), test_lei_airfoil_panel_vs_polar_input.
tests/WingGeometry/test_WingGeometry.py: test_refine_aerodynamic_mesh_1_panel (Julia's 'Single panel' testset reads the unrefined sections, so it checks the input).
tests/BodyAerodynamics/test_kite_global_properties.py: test_wing_span, test_aspect_ratio_projected, test_geometric_properties_mesh_independent.
tests/BodyAerodynamics/test_bridle_line_inflow.py: test_reference_point_is_stored_even_without_body_rates.
tests/Solver/test_solver.py: test_artificial_viscosity_stabilizes_post_stall, test_regularize_gamma_target_matches_dense_solve, test_artificial_viscosity_end_to_end_attached_identical_and_post_stall_smooth (Julia asserts only finite gamma).
tests/AirfoilAerodynamics/test_airfoil_aerodynamics.py: test_invalid_type_raises, test_breukels_regression_stall_logic.

Also: the nine reference cases in test/data/python_reference, on the branch of the pull request for #410, all run with the quarter-chord correction and leg force on, so the agreement with those two options off is unmeasured, and they do not store the centre of pressure, which has no value check with the leg force on. generate_reference.py there is how to get numbers from Python, run in a container. Python also compares its solves to its own older commit (tests/BodyAerodynamics/test_panel_kernels.py, panel_kernel_reference.npz); say whether Julia wants that. Build on the branch of the pull request for #410.