Pixel Tracking with Phi-sorted hits and Phi-search windows, Include Flags for…

This merge orverwrite what is in !910 (closed) , concerning usage of Phi-hits and sorting in Phi. Also, Flags for speed changing logic of the algorithm. In addition, flags for switching behavior to restore almost original tracking efficiencies of Pixel Tracking. Code clean-up, message level debug printout, more understandable methods description and logic within the algorithm. Introduction of VeloPixelInfo for size of offsets (was hardcoded) and number of velo modules (also hardcoded) and fastatan2 approximation. Already including hit buffer for chi2 track and NDOF fix from !925 (closed) FYI: @sponce, @chasse , @gligorov , @cattanem

To be addressed: Tolerances in bestHitChangeSide to deal with boundaries in phi for a given module are hard-coded