Add track extrapolation Functor

• Introduction of a Functor EXTRAPOLATE_TRACK defined in TrackLike.h that returns the state of a track extrapolated to a given z position
• Functor was tested on K_\mathrm{S}^0 candidates reconstructed in 1k events of Run 256166 at the centre of SciFi station T1 ( 7931mm as in FTTrackMonitor.cpp)
• Plots below show x-y distributions of \pi^+ and \pi^- originating K_\mathrm{S}^0 candidates without any selection applied, except for a invariant mass cut 50 MeV around the K_\mathrm{S}^0 PDG mass x-y distribution of \pi^+: pi_pl_XYT1.pdf x-y distribution of \pi^-: pi_mi_XYT1.pdf

Goes together with DaVinci!1121 (merged) (used to test the functor)