Receive enodes over websockets and serve them at /static-nodes.json

[d3alek]

Intention is to make eth-netstats a source of Auto-updated Enode List to use with Nethermind of example.

How it works: The enode-reporter is a separate NodeJS app that is designed to run besides Nethermind and query the Nethermind client via JsonRPC. Then it publishes enode and name on the enode channel via Websockets connection with eth-netstats. Here we collect all enodes (keyed on node id for deduplication purposes) and store them in the format of static-nodes.json, one of the config files for Nethermind.

The file is available at /static-nodes.json.