MPI improvements

**Is your feature request related to a problem? Please describe.**
I am thinking to further improve the MPI feature with a proper restart of the MPI program. The actual procedure to start an MPI program is. Use the script launch_mpi_debugger to launch the program in debug mode with every process sitening for connections. Than start the server, start the browser, select the MPI option and press connect. Restarting the program involve at the moment close the program, close the server. and follow the start procedure again. This is quite cumbersome.

**Describe the solution you'd like**
To have a proper restart procedure in the sense that the server is capable to close the mpi program, close all its opened sessions, and start it in listening mode or multiprocess mode,

Again I will handle this PR (Not sure when)

**Describe alternatives you've considered**
No alternatives

**Additional context**
No screenshot but, most probably I will add a further option. Where instead of connecting to multiple gdb-servers, you can run and restart MPI programs.

Start with the launch_mpi_debugger script and trace the server, browser, and MPI connect flow described in the issue. Define the restart path around closing the MPI program and its opened sessions, then verify that a program can be restarted in listening or multiprocess mode without repeating the full manual startup procedure.

Written by the indexing model from the issue text.