Addition of Low-Pt RoI tracking information to DAOD STDM7 derivation

@spagan @adimitri @npetters @goblirsc This is a companion merge request for !33769 (merged). The exclusive WW analysis team is implementing low-pt tracking within a region of interest, such that low-pt tracks can be constructed within a z-region of the beamline. The analysis uses DAOD_STDM7 as their analysis derivation. They want a separate container for the low-pt tracks, such that the production DAODs can easily be used to reproduce the generic analysis and can be used to do the version of the analysis with low-pt tracks. There is also a vertex container added that keeps track of the places within a beamspot where low-pt tracking was performed. The DAOD_STDM7 will not include these new containers unless the low-pt track and vertex containers are already in the AOD being slimmed. In this way, the content of the DAOD_STDM7 will be unchanged for all analyses that are not using low-pt RoI tracking.