fix (smartplug_usb): disable energy sensor by default and make optional

Other sensors are optional, but energy sensor (which is the least reliable
in general) was not. This should be hidden by default, as even when present
the add_ele (dp 17) sensors on Tuya smartplugs are not generally usable as
energy sensors.

custom_components/tuya_local/devices/smartplug_usb.yaml

@@ -103,9 +103,11 @@ entities:
   - entity: sensor
     class: energy
     category: diagnostic
+    hidden: true
     dps:
       - id: 17
         type: integer
+        optional: true
         name: sensor
         unit: kWh
         class: total_increasing