Support processing data from multiple campaigns
Goal: Support processing data from multiple campaigns, which is e.g. needed to run on the full Run 2 dataset (mc16a+mc16d+mc16e), in a user-friendly way.
Related changes in HWWAnalysisCode will be collected here: https://gitlab.cern.ch/atlas-physics/higgs/hww/HWWAnalysisCode/issues/36
The issue was discussed in the following meeting prior to the implementation: https://indico.cern.ch/event/786718/