Fix OpenLoop Path for Powheg-Box-Res processes ttbb and bblvlv
The changes in PowhegControl update the hack for OpenLoops path problem for the ttbb Powheg-Box-Res process - in order to not completely hardcode the path - and implements the same for bblvlv, as discussed in AGENE-1638. The same can be used for other Powheg-Box-Res processes if need be.