Implement /network/peers

[mmahut]

As we're approaching Ouroboros Genesis, we want to serve information about the peer snapshots.

The same as cardano-cli conway query ledger-peer-snapshot --help.

This is basically the relays of the largest pools that cumulatively hold 90% of total stake.

The output of the cli is:

{
  "bigLedgerPools": [
    {
      "accumulatedStake": 0.004156807533298409,
      "relativeStake": 0.004156807533298409,
      "relays": [
        {
          "domain": "77cb3f75.cardano-relay.herd.run",
          "port": 1338
        }
      ]
    },
    {
      "accumulatedStake": 0.007964615279184796,
      "relativeStake": 0.003807807745886388,
      "relays": [
        {
          "domain": "relays-8a.cardano.2k2aa.com",
          "port": 3001
        },
        {
          "domain": "relays-8b.cardano.aeq5f.com",
          "port": 3001
        }
      ]
    },
    {
      "accumulatedStake": 0.011611680271961581,
      "relativeStake": 0.0036470649927767846,
      "relays": [
        {
          "domain": "relay-kiln-0-0.cardano.mainnet.kiln.fi",
          "port": 3001
        },
        {
          "domain": "relay-kiln-0-1.cardano.mainnet.kiln.fi",
          "port": 3001
        },
        {
          "domain": "relay-kiln-0-2.cardano.mainnet.kiln.fi",
          "port": 3001
        }
      ]
    },
    {
      "accumulatedStake": 0.015134695072175979,
      "relativeStake": 0.003523014800214398,
      "relays": [
        {
          "domain": "cardanosuisse.com",
          "port": 170
        },
        {
          "domain": "cardanosuisse.com",
          "port": 171
        },
        {
          "domain": "cardanosuisse.com",
          "port": 172
        }
      ]
    },
    {
      "accumulatedStake": 0.01864999463282789,
      "relativeStake": 0.0035152995606519103,
      "relays": [
        {
          "domain": "relays.bladepool.com",
          "port": 3001
        }
      ]
    },
    {
      "accumulatedStake": 0.02216514996218333,
      "relativeStake": 0.0035151553293554403,
      "relays": [
        {
          "address": "148.113.17.23",
          "port": 6000
        },
        {
          "address": "158.69.25.103",
          "port": 6000
        },
        {
          "address": "95.216.4.252",
          "port": 6000
        },
        {
          "address": "178.18.250.204",
          "port": 6000
        }
      ]
    },
    {
      "accumulatedStake": 0.025660698392526615,
      "relativeStake": 0.0034955484303432825,
      "relays": [
        {
          "address": "95.154.235.142",
          "port": 6000
        },
        {
          "address": "217.155.18.115",
          "port": 6003
        },
        {
          "address": "217.155.18.115",
          "port": 6001
        }
      ]
    },

(...)

But we can make our own output if this is a blocker.