Handle panics during checking about stateright HOT 1 CLOSED

Absolutely. This is something that has bothered me as well, and I would love to surface these in the Explorer UI. Recording all panics seems like a nonstarter, so one option is to simply surface one panic (or up to one per thread, but even that seems more than necessary). Off the top of my head I imagine it would involve:

1. Add the needed "panic" field to each checker (e.g. DfsChecker).
2. Update the Checker::join implementations accordingly.
3. Introduce a Checker::panic accessor.
4. Revise the Reporter implementation(s) and the Explorer UI.
5. Make changes so that panics aren't missed when asserting properties (Checker::assert_properties should probably propagate the panic). That could possibly be done at a lower level like Checker::assert_no_discovery.

from stateright.