DB Migration - Add new Model: Server

[tomsmith8]

Task

Initially it will have just one record but could have more than one LSP servers in the future. For now, use one LSP record:

• ip: Ip of the server (string)
• pubKey: pubKey of the LSP server (string)

Acceptance Criteria

• Implement db change for ip and pubKey for one LSP record
• Check ip and pubKey for one LSP record