Merge of online and offline particle flow run 3 configs, add new run 3 config files for track extrapolation and calibration hit decorators.
requested to merge atlas-particleflow-software/athena:mhodgkin_mergeOnlineOfflinePFConfigs_Dec2019 into master
This MR merges the online and offline run 3 particle flow configs as far as currently possible, by creating common config functions for both to use. I also added an update to how the magnetic field service is configured in the offline pflow case. I also added new config files for the track extrapolation caching (now needed by offline pflow) and calibration hit decoration algorithms.