Changing how FTF can be run as an offline algorithm for ITk
Adding new offline ITk tracking flag to enable FTF to run as offline algorithm by replacing SiSPSeededTrackFinder. FTF is already able to run as an offline algorith with Reco_tf via a standalone file, TrigFastTrackFinder/ITkFastTrackFinderStandaloneConfig which is added as a --postInclude option. This was first included with !56436 (merged). Since then, this way of running FTF has been vital for continued development and optimisation, and is also used in the nightly ART tests test_run4_mu100_FTF and test_run4_ttbar_PU200_FTF.
This merge request introduces a new way of running FTF as an offline algorithm in which FTF replaces the offline SiSPSeededTrackMaker in the offline configuration if a new offline ITk tracking flag, ConfigFlags.ITk.Tracking.useFTF, is set to true. This way of running FTF had been suggest multiple times when presenting performance comparisons between offline and FTF as a part of EFTRACK-7.
As this only impacts how FTF is ran with ITk, this merge request targets master.