Ion coagulation Example

[Gorkowski]

Add example to reproduce Ion-particle paper by @mahf708

[github-actions]

This will be closed soon due to inactivity

[Gorkowski]

@mahf708 what paper-figure did you want to copy for this? or do you want to save this for AAAR

[mahf708]

Pfeiffer et al 2023

[Gorkowski]

moved this to a discussion, on tracking charges in simulations. So we still remember it, but can clean up our issues list.
#796