Make module names consistent and remove redundant module casting (#909)

Address the inconsistent naming of smart modules by removing all "Module" suffixes and aligning filenames with class names. Removes the casting of modules to the correct module type now that is is redundant. Update the adding of iot modules to use the ModuleName class rather than a free string.

kasa/smart/modules/batterysensor.py

@@ -0,0 +1,54 @@
+"""Implementation of battery module."""
+
+from __future__ import annotations
+
+from ...feature import Feature
+from ..smartmodule import SmartModule
+
+
+class BatterySensor(SmartModule):
+    """Implementation of battery module."""
+
+    REQUIRED_COMPONENT = "battery_detect"
+    QUERY_GETTER_NAME = "get_battery_detect_info"
+
+    def _initialize_features(self):
+        """Initialize features."""
+        self._add_feature(
+            Feature(
+                self._device,
+                "battery_low",
+                "Battery low",
+                container=self,
+                attribute_getter="battery_low",
+                icon="mdi:alert",
+                type=Feature.Type.BinarySensor,
+                category=Feature.Category.Debug,
+            )
+        )
+
+        # Some devices, like T110 contact sensor do not report the battery percentage
+        if "battery_percentage" in self._device.sys_info:
+            self._add_feature(
+                Feature(
+                    self._device,
+                    "battery_level",
+                    "Battery level",
+                    container=self,
+                    attribute_getter="battery",
+                    icon="mdi:battery",
+                    unit="%",
+                    category=Feature.Category.Info,
+                    type=Feature.Type.Sensor,
+                )
+            )
+
+    @property
+    def battery(self):
+        """Return battery level."""
+        return self._device.sys_info["battery_percentage"]
+
+    @property
+    def battery_low(self):
+        """Return True if battery is low."""
+        return self._device.sys_info["at_low_battery"]