Add feature to retrieve 'Away Mode' from the device API

[rsocko]

Option 1:

• Add a single new property (bool) to indicate if Away mode is enabled (true) or disabled (false)
• This will call the API:
  return await self._request("get", f"{API_BASE}/preferences/device/{device_id}/leak_sensitivity_away_mode")

Option 2:

• Use the preferences API to pull the full dictionary of preference settings (which includes the leak_sensitivity_away_mode)
• Expose the dictionary / array similar to the get_state method
• Call this API:
  return await self._request("get", f"{API_BASE}/preferences/device/{device_id}")

For ease of debugging, add an update to the device_dump.py file to also output the data that is gathered either in option 1 or option 2.

It would also be possible to add both (a preferences dictionary + a directly accessible property getter method)

[rsocko]

Note I have taken a fork of the project to work on this feature. If there are any preferences (on the above) or process preferred for pull requests, etc. please let me know.

[rsocko]

I have completed option 1 - added a new method to return the away_mode value.

This is returned as a dictionary that contains the last updated and set time stamp. Those attributes are exposed by the aiophyn interface as the return value.

[rsocko]

#4 is the pull request for this feature implemented.