Restrict preCICE time for selected tests

[MakisH]

Some tests are expected to be taking too long to run. For such cases, it would be nice to have an option to overwrite the max-time in the precice-config.xml, both for running the test and for the reference results. Something like this in the tests.yaml:

  openfoam_adapter_pr:
    tutorials:
      - path: flow-over-heated-plate
        case_combination:
          - fluid-openfoam
          - solid-openfoam
        reference_result: ./flow-over-heated-plate/reference-data/fluid-openfoam_solid-openfoam.tar.gz
        max_time: 0.5

which would then perform the following change:

- <max-time value="1" />
+ <max-time value="0.5" />

Motivation: Some tutorials are long either to showcase a nice effect to the user, or because a benchmark defines the length. However, the system tests need to be running in reasonable time frame in order to be useful for developers.