fix matchbox+herwig7 muons that travel large distances

This commit enables the fixSeq when running an afterburner. It turns everything off by default. No default functionality has changed. This code modifies HepMC if there is a very displaced muon coming from a status 11 muon, then move the vertex position to the status 11 start vertex. This is patching a bug in the Matchbox+H7 interface that allows muons to travel a 10s of km. This resulted in the muons not being reconstructed. The HepMCTests were disabled when these samples were generated. They now run well after this fix. These commits are to patch what should be the default NLO EWK Zmm+jets and NLO EWK Wmunu+jets samples on ATLAS. These replace the sherpa LO samples that have a major colorflow bug. These H7 samples agree the best with the ATLAS EWK Z+jets analysis.

Here is the reference to the JIRA documenting the problems with these samples. So far there isn't a fix from the H7 authors. Ideally it would have been fixed that way, but these samples are needed for Moriond. So we request this patch goes in. https://its.cern.ch/jira/browse/ATLMCPROD-7367

I cc'ed those the people that I think are relevant. I know this is not everyone's preferred solution, but these samples are needed. This path is under our control to fix. cc: @othrif @dgillber @dyallup @zmarshal @amoroso @cgutscho @aknue @temoskal @lcorpe @ewelina