Only run CutFlowSvc when explicitly configured and wanted
Only run CutFlowSvc
when explicitly configured and wanted. This is in the following two cases
- event filtering is done (usually the derivation level)
- cut bookkeepers already exist in the input file
This MR effectively disables cutflow in the Reco chain which was desired as no filtering is done there.
Has already been full-unit-tested in !37789 (merged), this just splits this change out.