Release of Gauss v55r4 for Sim10

This release is based based on Gauss v55r3 and introduce new functionality as well as pick up some modernisation to ease maintenance and the transition to Gauss-on-Gaussino

It is based on Gaudi v36r4 and LHCb v55r6 and LCG_101 with the LHCB_7 layer (that was updated to use the optimised compilation of pythia 8 (see LHCBGAUSS-2443, LBCORE-2050)

It requires a new release of Run2Support v2r1 and Geant4 v106r2p5

It also provides new features for

• Fast simulation and training data set
• Material scan
• A new UserHooks for Pythia8 to enhance b production
• Support for Velo Run3 (VP) misalignment and open position

For detailed list of MR refer to milestone