Check for existence of Timerclient before creating a new entry

[burmudar]

When a websocket client connects a TimerClient is immediately registered. This is naturally not ideal as the client might have previously connected and already have a entry in the DB.

The flow should be:

1. Websocket client connects
2. Server asks client to identify itself with a UUID
3. Check UUID
4. Confirm existence of client and send related configs to client.

The above flow can be implemented with a FSM