Remove remaining direct storegate accesses in LumiBlockComps
This is related to ATLASRECTS-4695, removing direct storegate accesses from LumiBlockComps. Note that this also includes a migration to xAOD::EventInfo, and one potential difference is that for data, the old EventInfo will no longer have the average and actual interactions per bunch crossing set. Having it set required a const_cast. The information should be there in xAOD::EventInfo, though.
Also noting that ATLASRECTS-4614 follows needed upgrades to the code in LumiBlockComps. There are still callbacks that need to be migrated. That is not part of this MR.