Create common interfaces for remaining device types (#895)

Introduce common module interfaces across smart and iot devices and provide better typing implementation for getting modules to support this.

kasa/iot/modules/__init__.py

@@ -5,6 +5,7 @@ from .antitheft import Antitheft
 from .cloud import Cloud
 from .countdown import Countdown
 from .emeter import Emeter
+from .ledmodule import LedModule
 from .motion import Motion
 from .rulemodule import Rule, RuleModule
 from .schedule import Schedule
@@ -17,6 +18,7 @@ __all__ = [
     "Cloud",
     "Countdown",
     "Emeter",
+    "LedModule",
     "Motion",
     "Rule",
     "RuleModule",