RFC: Output - Reduce reported checks/properties

[adpaco-aws]

Requested feature: Kani's output quickly gets cluttered due to the high number of checks being reported, and assumes that all properties have the same value. We need a proposal to change this. The goal is to:

1. Reduce the number of checks presented to the user as much as possible.
2. Keep checks that users care about.
   It isn't entirely clear how to do (2), but one can filter in checks in the user's code or checks whose status is deemed relevant despite not being in the user code.

Use case: Standard verification reports.
Link to relevant documentation (Rust reference, Nomicon, RFC): N/A

[JustusAdam]

Alternatively we could make sure the checks are sorted by importance or a full log is dumped somewhere and only the main gist is provided on stdout.