Come up with a plan for our efforts of finding similar relays

We want at some point figure out what similar relays to a relay X or a group of relays XYZ means. We should look at the literature and proposals that showed up in the past to create a plan and follow-up tickets.

https://lists.torproject.org/pipermail/network-health/2021-April/000672.html and phw's work around sybil hunting are good starting points here.