* Initialize children's modules (and features) using the child component negotiation results
* Set device_type based on the device response
* Print out child features in cli 'state'
* Add --child option to cli 'command' to allow targeting child devices
* Guard "generic" features like rssi, ssid, etc. only to devices which have this information
Note, we do not currently perform queries on child modules so some data may not be available. At the moment, a stop-gap solution to use parent's data is used but this is not always correct; even if the device shares the same clock and cloud connectivity, it may have its own firmware updates.
The initial steps to modularize the smartdevice. Modules are initialized based on the component negotiation, and each module can indicate which features it supports and which queries should be run during the update cycle.
This adds a generic interface for all device classes to introspect available device features,
that is necessary to make it easier to support a wide variety of supported devices with different set of features.
This will allow constructing generic interfaces (e.g., in homeassistant) that fetch and change these features without hard-coding the API calls.
`Device.features()` now returns a mapping of `<identifier, Feature>` where the `Feature` contains all necessary information (like the name, the icon, a way to get and change the setting) to present and change the defined feature through its interface.
