Add plot to monitor Stand Alone Muons Seed in the recoMuons validation DQM

This pull request  will add a plugin called "SeedToTrackProducer" in the SimMuon/MCTruth/plugins directory. It produces tracks from STA seeds which can be used by the MuonAssociatorByHits

This pull request contains also the changes in the RecoMuon validation sequence that will add a directory in the DQM output containing the plots in order to monitor the STA alone muon seeds.

This change has been tested on RelVals and has been approved by Giovanni, the muon POG convener.