Task #8437: Add support for global fs in node scripts to prevent rsyncing files within the same filesystem

Task #7491: Small rename of variables. Add output of correct files per image (including skip set), not used in the pipeline but for validity

It is not part of the current design. Tested in locus102 in integration test. 

Task #5028: merge from release branch to changes needed to run in juropa. Excluding parset adaptions

Task #4518: add beamtables again in prepare step: the bbs failed before. investigate the total time to run with a full bbs run

- Implement a mapfile replacement: DataMap adding a skip field to the host, file pair.
msss_target_pipeline and msss_calibrator_pipeline do now implement the skip behaviour for dataproduct.
msss_imaging_pipeline use the new DataMap and MultiDataMap classes for dataproduct communication. Does NOT listen to the skip field (default behaviour)
- Some minor changes in the location of imports (from start of module to function) to allow running of unittest on windows
- Update of the unittest to reflect the new behaviour and adding of DataMap unittests