Improve version management

One of our highest cost are silent behavior change in Qt. Because of Hyrum's Law we run constantly in trouble with new Qt versions which are changing the behavior without compile errors(ABI compability). To work around it I propose that we only support one Qt version officially. There will be a setting to disable the version checks so people still can test newer versions.

Our error on warning system be can maybe only enabled inside of the super repository to produce less noise for other. But that has the drawback that we get code with broken commits. So for very merge that has to be fixed.

We have hard dependencies to private API which can change with every minor version. Support multiple version can get much work too.