Validation of FMUs

[StephanieKemna]

From Christian:

Please note that FMUcheck does only a static validation of the FMU, it would be great to use also the other tools listed on https://fmi-standard.org/validation/ (fmpy or fmusim from the Reference FMUs) to simulate the FMUs, and add this information to the Readme.

So, we should:

• try other tools, e.g. fmpy/fmusim for each FMU
• update the README with which additional validation tools were used.

ref #77