Spam Activity Gossiping

[cameri]

Is your feature request related to a problem? Please describe. This requires #41 and for relays to be able to sign events. At a certain interval, share IP addresses and pubkeys engaged in spam with other participating relays. Spam notifications should include proof that the spam occurred. Accepting spam notifications require whitelisting the public key of the relays producing such events.

Describe the solution you'd like TBD

Describe alternatives you've considered https://github.com/ssbc/epidemic-broadcast-trees

Additional context None