GenericGenCutToolWithDecay now sets signal_process_vertex. Needed for ReDecay support for some GenXicc event types.
Port the merge of branch 'dmuller-LHCBGAUSS-1766' into 'Sim09-upgrade'
Corresponds to merge request !490 (merged) into 'Sim09' and !505 (merged) into 'master'
(cherry picked from commit 88faecc7)
6378518c GenericGenCutToolWithDecay now sets signal_process_vertex. Needed for ReDecay support