Linkage of Primary and Secondary Particles

[alexbooth92]

[lcrem]

Adding information about this issue: there is currently no link between true primary and true secondary particles, so we have no way to know if a particle reinteracted.

[jdkio]

I have some experience with edep sim particle trajectories. I'd need to familiarize myself with how it's all implemented here so it's not a trivial on-ramp for me, but I'm happy to help out