Cleanup TrackChecker
Remove unused track_best_matched_MCP
, that used to store the MCP to which a track was matched with the highest weight. Given that the MC checker for tracking efficiencies calculates them only based on the number of reconstructible MCPs and the number of reconstructed MCPs (i.e. those to which a track was matched), track_best_matched_MCP
is not needed and a relic from previous versions of the TrackChecker.