Support child devices in all applicable cli commands (#1020)

Adds a new decorator that adds child options to a command and gets the
child device if the options are set.

- Single definition of options and error handling
- Adds options automatically to command
- Backwards compatible with `--index` and `--name`
- `--child` allows for id and alias for ease of use
- Omitting a value for `--child` gives an interactive prompt

Implements private `_update` to allow the CLI to patch a child `update`
method to call the parent device `update`.

Example help output:
```
$ kasa brightness --help
Usage: kasa brightness [OPTIONS] [BRIGHTNESS]

  Get or set brightness.

Options:
  --transition INTEGER
  --child, --name TEXT            Child ID or alias for controlling sub-
                                  devices. If no value provided will show an
                                  interactive prompt allowing you to select a
                                  child.
  --child-index, --index INTEGER  Child index controlling sub-devices
  --help                          Show this message and exit.
```

Fixes #769

kasa/iot/iotstrip.py

@@ -145,7 +145,7 @@ class IotStrip(IotDevice):
 
         if update_children:
             for plug in self.children:
-                await plug.update()
+                await plug._update()
 
         if not self.features:
             await self._initialize_features()
@@ -362,6 +362,14 @@ class IotStripPlug(IotPlug):
 
         Needed for properties that are decorated with `requires_update`.
         """
+        await self._update(update_children)
+
+    async def _update(self, update_children: bool = True):
+        """Query the device to update the data.
+
+        Internal implementation to allow patching of public update in the cli
+        or test framework.
+        """
         await self._modular_update({})
         for module in self._modules.values():
             module._post_update_hook()