Add shelly overcurrent sensor for switches (home-assistant#122494)

shelly: add overcurrent sensor for switches

just like overvoltage shelly switches can react to overcurrent and
diable the switch. Unfortunately this is is not mentioned anywhere in
the documentation.
It can be triggered by a device using more amps than set in
"Output protections" under the name "Overcurrent in amperes".

homeassistant/components/shelly/binary_sensor.py

@@ -204,6 +204,15 @@ class RestBinarySensorDescription(RestEntityDescription, BinarySensorEntityDescr
         entity_category=EntityCategory.DIAGNOSTIC,
         supported=lambda status: status.get("apower") is not None,
     ),
+    "overcurrent": RpcBinarySensorDescription(
+        key="switch",
+        sub_key="errors",
+        name="Overcurrent",
+        device_class=BinarySensorDeviceClass.PROBLEM,
+        value=lambda status, _: False if status is None else "overcurrent" in status,
+        entity_category=EntityCategory.DIAGNOSTIC,
+        supported=lambda status: status.get("apower") is not None,
+    ),
     "smoke": RpcBinarySensorDescription(
         key="smoke",
         sub_key="alarm",