AnalysisTop: Retrieve DSID from metadata when CollectionTree is empty
Recent changes in AnalysisTop broke the ability to run over dAOD with empty CollectionTree without crash. This is needed for skimmed MC samples for proper calculation of pre-skim sum of weights.
The problem is related due to necessity to retrieve DSID which was previously only retrieved from CollectionTree. In this MR, we add reading of DSID from FileMetaData or TruthMetaData.
Fixes ANALYSISTO-912
Edited by Oliver Majersky