Add new track state locations inside the magnet region and a Golden-Section minimisation algorithm
This MR introduces new track state locations (BegMagnet, MidMagnet, EndMagnet) that will be used for T-track extrapolation. This accelerates computation and enables the use of the TrackTraj and' TrajPoca` algorithms.
Also, a GoldenSectionMinimizer minimisation algorithm is added to LHCbMath. It's required by the new GSIP functor, which is developed in Rec!4542.
Finally, this MR extends the interface of LHCb::State by adding friend members referencePoint and slopes.
The deviation of `TrackTraj` interpolation with the new states from a full Runge-Kutta track extrapolation
Edited by Volodymyr Svintozelskyi