Contract snapshot reported on failure

[BowTiedRadone]

During a live Rendezvous demo, @cylewitruk made a good point about taking a snapshot of contract data variables right before something breaks. This would translate into taking a snapshot for each run, overwrite the old one, and report on failure. We should think about adding this feature after checking if it would slow things down significantly.

[moodmosaic]

It'll be perf-wise faster if on failure we just replay with the seed and print the state.

[BowTiedRadone]

Fantastic! Since we know when the failure happened, we can replay everything up to just before it breaks, grab the state at that moment, and then share that info in the report.