Report relays that sbws sees in the consensus, but never chooses to test

We should count:

• the number of consensuses that sbws has seen a relay in the consensus
• the number of times sbws chooses to test a relay
• the number of times sbws chooses to exclude a relay (for example, because it's an authority)

If there are a large number of exclusions, we should split the exclusions into subcategories.