Fan presets: add a "Display off" preset, as implemented by Soleair.

PR #1327

custom_components/tuya_local/translations/en.json

@@ -174,6 +174,7 @@
                             "fresh": "Fresh",
                             "smart": "Smart",
                             "strong": "Strong",
+                            "displayoff": "Display off",
                             "off": "Off"
                         }
                     }