Add LLP DF flags + option to save full truth content; temporary fix to InDetTrackTruthFilterTool

This MR adds a new set of flags for Derivation.LLP, and an option in LLP1 to save the full truth particle and vertex containers with the preExec:

--preExec='flags.Derivation.LLP.saveFullTruth=True'

This also adds a flag to turn on/off running the extra track systematics, and sets it to False by default to avoid saving unnecessary information for background MC samples. The InDetTrackTruthFilterTool is also updated to fix an issue in LLP1 and IDTR2 do to a missing histogram (to be fixed once a new file is installed in the CalibArea)

Tagging @emmat, @calpigia, @tstreble