migrate FastTimrService to the threadsafe signales, and reorganise the plots

Cache the first/last path and endpath names by string instead of by
pointer; this makes the comparison slower, but we should migrate to
pathIDs anyway.
In the long term it's not clear whether it makes sense to keep track
of the "first" and "last" paths in a multithreaded environment.
convert FastTimerFilter to a global EDFilter, and adapt to the threadsafe FastTimerService
add a FastTimer based on std::chrono::high_resolution_clock
remove obsolete modules - please use the FastTimerService for any timing measurements instead
work in progress: re-implement the removed functionality once the new EventTimer is available
work in progress: add new timing dataformat
work in progress: add dummy EDProducer for the new edm::EventTimer