Migrate TrackVertexUtils.h to LHCb
The code in TrackVertexUtils is really just an extension of the LHCb::State interface, so to sort out a circular dependency in Rec the easiest solution (for this part) is to move this code into the same package as LHCb::State, which is Event/TrackEvent in LHCb.
In addition this MR moves some code between SelTools and SelKernel in order to reduce the circular dependencies. At this point, SelTools no longer depends on SelKernel, and there is only a mutual dependency between SelKernel and FunctorCore left...
must be applied in conjunction with LHCb!3466 (merged)
Edited by Gerhard Raven