Gautone alarm: add alarm_message as extra attribute

- add message attribute to alarm sensor, to pass on the dp 26 base64 value
- add binary sensors for low battery and mains power based on dp 101.

Issue #1059

custom_components/tuya_local/devices/gautone_pg103_alarm.yaml

@@ -111,4 +111,32 @@ secondary_entities:
             value: false
           - dps_val: alarm
             value: true
+      - id: 26
+        type: base64
+        name: message
+        optional: true
+        persist: false
+  - entity: binary_sensor
+    class: battery
+    category: diagnostic
+    dps:
+      - id: 101
+        type: string
+        name: sensor
+        mapping:
+          - dps_val: BatteryIsLow
+            value: true
+          - value: false
+  - entity: binary_sensor
+    class: plug
+    category: diagnostic
+    dps:
+      - id: 101
+        type: string
+        name: sensor
+        mapping:
+          - dps_val: powerDisconnect
+            value: false
+          - value: true
+