Tkdetmap threadfix

TkDetMap made thread-safe with minimal changes: still kept as a Service, but issue reported here:
https://twiki.cern.ch/twiki/bin/view/CMSPublic/FWMultithreadedServicesReview#TkDetMap

should be now avoided by moving the cached_detid and cached_layer data members outside the class.

This is a temporary fix in order to put back asap all the DQM modules removed from sequences:
https://github.com/cms-sw/cmssw/commit/fa306b4747c95e12ff12d772b845d0cb7256de27