powerworld_pw58330_waterheater: Added unit % to 'Coefficient of performance' to have a propper graph and not only a changing string. Actualy it is a factor but I didn't find a unit for that.

custom_components/tuya_local/devices/powerworld_pw58330_waterheater.yaml

@@ -452,6 +452,7 @@ entities:
         type: base64
         optional: true
         name: sensor
+        unit: '%'
         mapping:
           - scale: 10
         mask: "0000000000000000000000000000000000000000FFFFFFFF\