Added property to AthenaOutputStream to list provenance tags to keep ATEAM-1050
This MR introduces AthenaOutputStream String property 'KeepProvenanceTagsRegEx' that may be used to match processing tags in Event provenances and copy only matching provenance to the new DataHeader.
Empty regex string means clear all input provenance (but if keepProvenance is True, the immediate source provenance will be still stored).
python OutputStreamCfg() method accepts optional KeepProvenanceTagsRegEx parameter that will be copied to the C++ property (unless it is None (the default))
Edited by Marcin Nowak