Jet core dedicated tracking

Conflicts:
	RecoTracker/CkfPattern/src/TrajectorySegmentBuilder.cc
	RecoTracker/FinalTrackSelectors/python/MergeTrackCollections_cff.py
	RecoTracker/IterativeTracking/python/iterativeTk_cff.py
Jet core dedicated tracking
change a couple of parameters to be closer to the other tested config
remove PXB2

Conflicts:
	RecoTracker/FinalTrackSelectors/python/MergeTrackCollections_cff.py
	RecoTracker/IterativeTracking/python/iterativeTk_cff.py
remove hard coded stuff
fix compilation errors
switch to iter7
seeding layers ed producer
fix pvSrc and add jet filter to sequence
using track jets and pixel vertices (and fixing MTE for the region) it runs
add validation of jet core step
cleanups
remove clusters from JetCoreRegionalStep
Revert "remove clusters from JetCoreRegionalStep"

This reverts commit a6a6ffd6170c33ed745226cc618f18ccddafa6d7.
put jetcore step at the end
added new tagging variables and new version of CombinedSVComputer
minor fixes
combined CSVV2+SL tagger
changes needed or combined CSVV2_SL tagger
if-else instead of ifs and removing the unneeded exception