[ci][wip] moving  files for monolithic case from FVCA in similar file structure as for partitioned case

- Python script driving the partitioned tests is no also running the diff and cleaning up the directory the test is running in.
- As a consequence the CMakeLists.txt for the tests (FVCA) could be simplified

Cleanup test directory

See merge request !11

Increase flow velocities for partitioned tests

See merge request !10

[ci][wip] moving  files for monolithic case from FVCA in similar file structure as for partitioned case