Interfaces should be in Husqvarna package

[Jeff Winn]

Is your feature request related to a problem? Please describe:
While reviewing the code structure I noticed the interfaces used to manage the switches and sensors are co-located with the services that implement the interface.

Describe the solution you'd like:
In this very specific scenario, those interfaces were abstractions over automower and belong in the Husqvarna package instead. They’re just one level too deep at the moment.

Describe alternatives you've considered:
Leaving them where they are placed, however if the Gardena mowers do become supported the structure will not be correct.

Additional context:
This is really just for maintaining the plug-in, it isn’t a high priority.