Fix set_state for common light modules (#929)

PR contains a number of fixes from testing with HA devices:

- Fixes a bug with turning the light on and off via `set_state`
- Aligns `set_brightness` behaviour across `smart` and `iot` devices
such that a value of 0 is off.
- Aligns `set_brightness` behaviour for `IotDimmer` such that setting
the brightness turns on the device with a transition of 1ms. ([HA
comment](https://github.com/home-assistant/core/pull/117839#discussion_r1608720006))
- Fixes a typing issue in `LightState`.
- Adds `ColorTempRange` and `HSV` to `__init__.py`
- Adds a `state` property to the interface returning `LightState` for
validating `set_state` changes.
- Adds tests for `set_state`

kasa/interfaces/light.py

@@ -18,7 +18,7 @@ class LightState:
     hue: int | None = None
     saturation: int | None = None
     color_temp: int | None = None
-    transition: bool | None = None
+    transition: int | None = None
 
 
 class ColorTempRange(NamedTuple):
@@ -128,6 +128,11 @@ class Light(Module, ABC):
         :param int transition: transition in milliseconds.
         """
 
+    @property
+    @abstractmethod
+    def state(self) -> LightState:
+        """Return the current light state."""
+
     @abstractmethod
     async def set_state(self, state: LightState) -> dict:
         """Set the light state."""