Add Ventilation RPM sensor to heatpump configuration (#4221)

* Add Ventilation RPM sensor to heatpump configuration

Added Ventilation RPM sensor with diagnostic category.

* Rename 'Ventilation RPM' to 'Fan'

* Remove class property from Fan entity

Removed the 'class' property from the Fan entity.

* Rename 'Fan' to 'Fan speed'

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Co-authored-by: Jason Rumney <make-all@users.noreply.github.com>

custom_components/tuya_local/devices/steinbach_solid_4.3_heatpump.yaml

@@ -72,3 +72,13 @@ entities:
       - id: 21
         type: bitfield
         name: fault_code
+  - entity: sensor
+    name: Fan speed
+    category: diagnostic
+    icon: mdi:fan
+    dps:
+      - id: 114
+        type: integer
+        optional: true
+        name: sensor
+        unit: rpm