Gadgetbridge can be configured to perform an action when a
Huami device is taken off or the user was detected to fall asleep or
wake up. This functionality was specific to Huami devices, but this
changeset moves this upstream to the AbstractDeviceSupport class in
combination with new GBDeviceEvents.
Now that the ADS has centralized support for this functionality, the
same logic can be used for other devices. In this case, an
implementation is added for supported Xiaomi devices.
