Add childlock module for vacuums (#1461)

Add new configuration feature:
```
Child lock (child_lock): False
```
---------

Co-authored-by: Steven B. <51370195+sdb9696@users.noreply.github.com>

tests/smart/modules/test_childlock.py

@@ -0,0 +1,44 @@
+import pytest
+
+from kasa import Module
+from kasa.smart.modules import ChildLock
+
+from ...device_fixtures import parametrize
+
+childlock = parametrize(
+    "has child lock",
+    component_filter="button_and_led",
+    protocol_filter={"SMART"},
+)
+
+
+@childlock
+@pytest.mark.parametrize(
+    ("feature", "prop_name", "type"),
+    [
+        ("child_lock", "enabled", bool),
+    ],
+)
+async def test_features(dev, feature, prop_name, type):
+    """Test that features are registered and work as expected."""
+    protect: ChildLock = dev.modules[Module.ChildLock]
+    assert protect is not None
+
+    prop = getattr(protect, prop_name)
+    assert isinstance(prop, type)
+
+    feat = protect._device.features[feature]
+    assert feat.value == prop
+    assert isinstance(feat.value, type)
+
+
+@childlock
+async def test_enabled(dev):
+    """Test the API."""
+    protect: ChildLock = dev.modules[Module.ChildLock]
+    assert protect is not None
+
+    assert isinstance(protect.enabled, bool)
+    await protect.set_enabled(False)
+    await dev.update()
+    assert protect.enabled is False