Support for new ks240 fan/light wall switch (#839)

In order to support the ks240 which has children for the fan and light
components, this PR adds those modules at the parent level and hides the
children so it looks like a single device to consumers. It also decides
which modules not to take from the child because the child does not
support them even though it say it does. It does this for now via a
fixed list, e.g. `Time`, `Firmware` etc.

Also adds fixtures from two versions and corresponding tests.

kasa/tests/smart/features/test_brightness.py

@@ -10,11 +10,13 @@ brightness = parametrize("brightness smart", component_filter="brightness")
 @brightness
 async def test_brightness_component(dev: SmartDevice):
     """Test brightness feature."""
+    brightness = dev.modules.get("Brightness")
+    assert brightness
     assert isinstance(dev, SmartDevice)
     assert "brightness" in dev._components
 
     # Test getting the value
-    feature = dev.features["brightness"]
+    feature = brightness._module_features["brightness"]
     assert isinstance(feature.value, int)
     assert feature.value > 1 and feature.value <= 100