When pinging an inaccessible device, OS errors like
ping: sendto: No route to host
can occur. For a ping tracker this is not an error but rather a normal
situation. Thus, it makes sense to hide the error.
* Add mysensors device_tracker platform
* Add discovery of device_tracker platforms
* Enable discovery of device_tracker platforms that are not
DeviceScanner.
* Update signature of setup_scanner function in all affected platforms.
* Add test.
* Use discovery for mysensors device_tracker platform.
* Remove gps accuracy
* Small change to core like schema
* fix depency
