Add support for MPI functionalities on windows

[alexandrebouchard]

Some MPI related tests are encountering what seems to be windows-specific, non-deterministic failures. For example, see CI results for commits:

• 8377ab5
• c513ee0

Since we recently spend considerable effort fixing platform-dependent MPI issues on linux and mac os, we are reasonably confident these are windows-specific issues. Since we expect that windows MPI will be much less common than running MPI on linux clusters, we are not supporting/testing MPI-related functionalities on windows at the moment (all the other features are tested and works successfully on windows).

[miguelbiron]

What we know so far: windows with

• the default MPICH_jll fails nondeterministically when n local mpi > 1
• MicrosoftMPI_jll has worked so far even with more than one mpi process -- but cannot rule out nondeterministic bugs