Provide additional information related to rejecting/badexiting etc. relays

With margot we only provide a link to the respective ticket number where the reasoning and further information behind a relay entry in our approved-routers.conf/bad.conf file got mentioned.

We have some directory authority operators who would like to have more information directly in those files instead of just in the related ticket. In particular useful would be:

Time of added entry
Who made the decision
Reason

The latter could easily get complex but we have a set of pretty common reasons we could use:

exit dns failures
proto/version mismatch
family not right
version too old
caught modifying exit traffic
we think they're the same as a previous attacker
alarming possible-sybil

Cases that do not fit into any of the above could get a longer explanation or maybe we need to expand the above list.