New fast pv3

From Silvio Donato @silviodonato and Andrea Rizzi @arizzi: define a few new modules that will be used for the future development of the HLT menu.
It is safe to include it in the 7_0_X release as none of the present modules or classes has been touched, and none of the possible present workflows will be affected. For the same reason, it cannot be tested with the present workflows or addon tests (this is just FYI).