In the context of ATLASRECTS-2807, the computation of the shared hit information is going to be moved from the Trk::TrackSummary into the xAOD::TrackParticle creation. The Analysis::Muon class implements interface with the Rec::TrackParticle but not the xAOD::TrackParticle. As the corresponding accessor methods do not appear to be used anywhere, they are simply removed. Going full-build full-unit-tests for safety