Use LHCB_5 layer with new generators
New generators are
- CRMC 1.8.0, for support of centrality events, see LHCBGAUSS-2179
- PowhegBox, new build.sh with added protection for the ZZ plugin
- Madgraph 2.7.3.atlas, for compatibility with python3 that requires at least this version
Closes LHCBGAUSS-2216