Multimuons new

This MR represents the completion of the puzzle in mass/lifetime space for Multimuon final states through potential long-lived intermediators. Several particularities are the following ones:

1. Sim09 request -> analysis could profit from the simulation of a similar previous analysis (search for B24mu decays) that had very similar needs. The overlap is large (maybe 50%) in simulation samples
2. As this summer is being targeted as a potential deadline, we ask for priority 1b, since otherwise all the production could delay everything.
3. Total events requested: 37M