Add colortemp module (#814)

Allow controlling the color temperature via features interface:
```
$ kasa --host 192.168.xx.xx feature color_temperature                                                                                                                             
Color temperature (color_temperature): 0

$ kasa --host 192.168.xx.xx feature color_temperature 2000
Setting color_temperature to 2000
Raised error: Temperature should be between 2500 and 6500, was 2000
Run with --debug enabled to see stacktrace

$ kasa --host 192.168.xx.xx feature color_temperature 3000
Setting color_temperature to 3000

$ kasa --host 192.168.xx.xx feature color_temperature                                                                                                                             
Color temperature (color_temperature): 3000
```

kasa/tests/smart/features/test_colortemp.py

@@ -0,0 +1,31 @@
+import pytest
+
+from kasa.smart import SmartDevice
+from kasa.tests.conftest import parametrize
+
+brightness = parametrize("colortemp smart", component_filter="color_temperature")
+
+
+@brightness
+async def test_colortemp_component(dev: SmartDevice):
+    """Test brightness feature."""
+    assert isinstance(dev, SmartDevice)
+    assert "color_temperature" in dev._components
+
+    # Test getting the value
+    feature = dev.features["color_temperature"]
+    assert isinstance(feature.value, int)
+    assert isinstance(feature.minimum_value, int)
+    assert isinstance(feature.maximum_value, int)
+
+    # Test setting the value
+    # We need to take the min here, as L9xx reports a range [9000, 9000].
+    new_value = min(feature.minimum_value + 1, feature.maximum_value)
+    await feature.set_value(new_value)
+    assert feature.value == new_value
+
+    with pytest.raises(ValueError):
+        await feature.set_value(feature.minimum_value - 10)
+
+    with pytest.raises(ValueError):
+        await feature.set_value(feature.maximum_value + 10)