Controlled Connection Retries

[afharo]

If you start / restart the Homebridge and the Xiaomi is off / battery is empty - then the plugin can not reach the robot.
It comes: "ERR connect | miio.device, next try in 2 minutes | Error: Could not connect to device, handshake timeout“ show here line 402.

Because the Homebridge does not get a Return / Error from homebridge-xiaomi-roborock-vacuum, the Homebridge hangs when the plugin is loaded and no devices in the Homebridge are accessible. In the Apple Home app, all devices from this Homebridge display "No Answer" or "Refresh“.

Instead of hanging forever until the device is connected, I've moved the retries to a setTimeout. That way the promise will either resolve or reject straight away. But we'll keep a retry to connect on every 2 minutes.

Still, whenever there's a new GET/SET request from HomeKit while still disconnected, it will try to connect again. Applying the same behaviour of resolving/rejecting the promise after the first attempt and schedule a reconnection attempt for later.