Arlec 19-speed fan: add scale to speed.

Add scale to speed, so it works across the full range, not just the bottom 20%.

Issue #543

custom_components/tuya_local/devices/arlec_19speed_fan.yaml

@@ -24,6 +24,8 @@ primary_entity:
       range:
         min: 1
         max: 19
+      mapping:
+        - scale: 0.19
     - id: 5
       name: oscillate
       type: boolean