Update RateMonitor to use DecReports
RateMonitor now uses DecReports from the HostBuffers to produce rate histograms instead of using the raw decisions and event offsets.
The following fields are once again only needed in the HostBuffers if running checkers: host_atomics_scifi, host_one_track_decisions, host_single_muon_decisions, host_sv_offsets, host_two_track_decisions, host_disp_dimuon_decisions, host_high_mass_dimuon_decisions.