Add a GPU-refit-to-propagation fallback (GPUTPCGMTrackParam::MoveToReference()/GPUTrackingRefit::RefitTrack() report whether they reached the reference X) so CalculatedEdx recovers rows where RefitTrackAsGPU() stalls, redesign same-row cluster handling into a configurable dEdxSettings::sameRowClusterMethod with a pad/time proximity gate, remove the duplicated legacy calculatedEdx() implementation in favor of the shared two-pass gatherRowClusterData()/calculatedEdxFromRowData() path, and simplify calculatedEdx.C into a single-threaded usage example

Author: tubagundem