Fixing issue with doFastTracking within patternCovariances
As title describes, an issue exists with the current setup of patternCovariances within SiTrajectoryElement_xk. This only occurs when setting ITk.Tracking.doFastTracking=True, and the issue is that the covariance should be left as is for strip clusters, but needs the changes applied for pixel clusters.
This was first discovered by a crash when trying to run the offline reconstruction for ITk with a single muon dataset. Furthermore, when running FastTrackFinder as an offline algorithm via ITk.Tracking.useFTF=True, the output efficiency histograms showed very poor efficiency in the 1<|eta|<3 regions relating to a significant descrease in tracks found in those regions. This merge request resolves both the low FTF efficiency and the crash in the offline reconstruction doFastTracking is used.
This merge request is only for upgrade, so targetting master.