Replace check_ws with subcription to websocket state

[jimmydoh]

uilibs/uiprotect@d7083ab removed check_ws, migrating the functionality to a websocket state subscription.

This PR adds the subscription, a callback to update self._websocket_state upon any state changes and replaces check_ws with self._websocket_state.

Continuation of discussions in PR #164

[ep1cman]

If the websocket is already connected by the time the event listener starts its internal state would be stuck on disconnected until the websocket disconnects and a reconnection is triggered?

I also don't think _check_websocket_and_reconnect needs to be run every 60s anymore because we can get a callback when the web socket disconnects