Recording start/stop/delete notifications should not trigger full model refresh

[andrewazores]

See also #344

In the Active Recordings Table component we listen for WebSocket notifications indicating that an active recording has been started, stopped, or deleted. If any of these occur then we trigger a full refresh of the table contents by firing a new HTTP GET request to the backend. Instead, the backend should include all relevant information about the recording that was started/stopped/deleted in the notification message, and the frontend should receive that message and use the recording information within to update the table state directly, without issuing an API request.