Fix ctest debian11
This MR makes the test suite pass on Debian 11. A tolerance in flow/tests/adjoint3.py
has been slightly increased. Slight modifications in the results seems to be due to another mesh generated by the newer gmsh installed in Debian 11.
I have also added a script to set the environment for building the code with VS2019 on Windows (see scripts/devenv-vs2019.bat
)