Use OSI pip install with pypi #69

Describe the feature

Currently OSI is a submodules, while parts of it (OSITracy.py) are not even used (see #55)
There is a current development in OSI to make it a PYPI package: OpenSimulationInterface/open-simulation-interface#800

Describe the solution you would like

Make the OSI PYPI package a dependency, and remove the submodule.
Then use the osi_tracy.py as an import from that package (solving #55).

Describe alternatives you have considered

Using OSI as a submodule would also work, but just making OSI a requirement will be a lot easier

Describe the backwards compatibility

This will entail and OSI update to upcoming version 3.7. But since OSI itself it backwards compatible, this should not impact backwards compatibility of osi-validation