Generalize smartdevice child support

* 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

kasa/smart/modules/childdevicemodule.py

@@ -1,4 +1,6 @@
 """Implementation for child devices."""
+from typing import Dict
+
 from ..smartmodule import SmartModule
 
 
@@ -6,4 +8,12 @@ class ChildDeviceModule(SmartModule):
     """Implementation for child devices."""
 
     REQUIRED_COMPONENT = "child_device"
-    QUERY_GETTER_NAME = "get_child_device_list"
+
+    def query(self) -> Dict:
+        """Query to execute during the update cycle."""
+        # TODO: There is no need to fetch the component list every time,
+        #  so this should be optimized only for the init.
+        return {
+            "get_child_device_list": None,
+            "get_child_device_component_list": None,
+        }