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/smart/smartdevice.py

@@ -171,7 +171,7 @@ class SmartDevice(Device):
         # devices will always update children to prevent errors on module access.
         if update_children or self.device_type != DeviceType.Hub:
             for child in self._children.values():
-                await child.update()
+                await child._update()
         if child_info := self._try_get_response(resp, "get_child_device_list", {}):
             for info in child_info["child_device_list"]:
                 self._children[info["device_id"]]._update_internal_state(info)