The source project of this merge request has been removed.
Draft: Externalise DTD and Add TrkRec Plots
Externalise DTD and add new TrkRec plots.
Baseline DTD is Run2, !ENTITY overrides in LRT and ITk xml. Run2/LRT shared plots deduplicated into share/InDetPVMPlotDefCommon_Run2LRT.xml
TrkRec plots are decoupled from all other plots, share only &ETA! definition.