Public API change from websocket messages to HTTP methods

[DJDuque]

I think it would be good to completely change the API from websocket messages to simple GET endpoints to retrieve e.g. plot and CSV data. We would loose the "interactive" messages of what commands have been launched, etc. But I think the ease-of-use is worth it.

[DJDuque]

Processing a request can take hours. Maybe some research is needed on timeouts (and how flexible they are) before committing to this.