Unable to determine reason for connection issues via error logs

[EuleMitKeule]

To my understanding there are at least two different reasons for the various connection issues described in #75, #71 and #65. One of them is a TimeoutError being raised when the notification / response by the thermostat takes too long after a request has been sent in bleakconnection._async_make_request_try and the other is raised when the BLEDevice or BluetoothScannerDevice is not returned by the Home Assistant bluetooth component in bleakconnection.async_get_connection. While both of these exceptions might have the same underlying cause, I think it would be helpful for debugging to differentiate between both errors by logging different error messages for either case.