New ECAL Unpacker code , off in sequences for the time being

New Ecalunpacker module from Philippe Gras. Not used in standard sequences for this PR. We plan to activate it at a later time.
there should be a consumes call in the constructor and also better use getByToken
https://twiki.cern.ch/twiki/bin/view/CMSPublic/SWGuideEDMGetDataFromEvent