web-map: Enable support for hosting multiple Factorio servers

[aSemy]

Presently the web-map only supports one Factorio server, as the URL is hard coded. However in the Kafka topics most (all?) messages are keyed by a Server ID - so that's a good start.

Supporting multiple servers requires authentication. It's possible to send a token along with a syslog message. This could be a JWT that contains a server ID. All messages must contain a server ID, and that can be mapped to a name. The tile-server can then use a new directory for each Factorio server.

• [x] events-server: Add some sort of authentication that will check incoming messages for a JWT token, and verify it
• [ ] web-map: add a new path per server? Not sure how to do this
• [ ] events-server: websocket clients should send a server ID and only subscribe to events for that server
• [ ] events-server: a table of registered servers, along with pertinent data (contact info, server name)

Out-of-scope

Nice to haves, but not necessary. Maybe in a later ticket.

• web-map: an overview page of all servers
• Kafkatorio portal: a web page where server owners can register a server and create their own keys

[aSemy]

Initial multi-server support has been implemented. Servers are identified with JWT authentication (manually created at the moment).