Dongguan electric curtain: naming changes

- Avoid use of superfluous terms like "Smart" in device names
- Name under products just needs to identify manufacturer and model, the top level name already describes the general purpose of the device
- no need to name the cover entity, as the class defines a translated name already.
PR #1698

custom_components/tuya_local/devices/dongguan_electric_curtain.yaml

@@ -1,10 +1,9 @@
-name: Smart curtain robot
+name: Curtain robot
 products:
   - id: kcy0x4pi
-    name: Dongguan LY1678-2 Electric Curtain Motor
+    name: Dongguan LY1678-2
 primary_entity:
   entity: cover
-  name: Curtain
   class: curtain
   dps:
     - id: 1