Extend PeerSelection tracer to include more information about local root peers

[Marcin Szamotulski]

We should log something like:

{ "groups": [
    { "warm": [
        { "address": "0.0.0.0",
          "port": 3001,
          "trustable": true,
        }      
        ],
     "hot": []
    }
  ]
}