Release first version of Run2Support
The first version of Run2Support should allow at least to merge Lamarr to Gauss reinstating the classes needed and removed from LHCb v51r3.
This could be decoupled with a separate tag - if not a release - allowing the merge of LHCb!2804 (merged) incorporating here what is in Gauss!664 (closed) so that Gauss could be releases against LHCb HEAD (still with LCG_97a_LHCB_N)