Fix quasi stable particle sim

MR to fix the calculation of the particle lifetime in quasi stable particle simulation. This issue was seen during the validation, see ATLASSIM-172 and https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PLOTS/FTAG-2020-002/. The old calculation used only the vertex information to calculate the lifetime. However, at least with some generators, the vertex information was numerically not sufficiently precise, so the calculation is now changed to use only the vertex space-distance and take the time information from the particle 4-momentum propagation