Clear contact slices either when virus free or path reconstruction is applied the same day

Below is actually about declaring the infector and solved in corresponding system. This issue is about tracing and will potentially be linked to time or so, dep. on how tracing is actually applied.

Likely slices can be cleared when infection path reconstruction system is applied the same day.

This system will randomly chose a contact of farm x which is assigned to be the contact who infected farm x, considering probability weighting.