Added error code for "Water level low" indication.

The name of this in the schema suggests that this is the primary or only use
for this dps, but there may be additional values, so leaving the possiblity
open and returning strings for recognized errors, and numbers for unrecognized.

custom_components/tuya_local/devices/eanons_humidifier.yaml

@@ -25,6 +25,8 @@ primary_entity:
       mapping:
         - dps_val: 0
           value: OK
+        - dps_val: 1
+          value: Water Level Low
     - id: 10
       name: hvac_mode
       type: boolean