Add truth parent hadron barcode for HF tracks
In order to link tracks to the saved truth hadrons, we save the barcode of the parent B/C hadron for each HF track. The values can be thought of as defining a non-spatial secondary vertex (where vertex = tracks coming from the decay of a hadron, rather than tracks with a similar production vertex position). This might be preferable in some ways to the truth vertices we are using at the moment, as we don't have to worry about merging nearby vertices, and it gives us a clean way to look only at secondary/tertiary vertices.
The information written out for the EMPFlowAll.json and EMPFlowTruth.json configs, but is only really useful for the EMPFlowTruth.json config, when we save the hadrons. I think there is an argument for adding the truth information to EMPFlowAll.json, and just removing the EMPFlowTruth.json config. I have done this, and replaced the truth test with a test for EMPFlowAll.json.
I also removed some DIPS/DL1 scores from the EMPFlowAll.json that are not present in the p4724 samples, and so cause an error.