fix(klarstein_ava_extractorhood): fix fan speed mappings

From Klarstein Alina info on Issue #5125
DPS info agrees with text of PR #4424 for Klarstein Ava, the current
mappings seem to be because the original PR had the dps_val and value
swapped, so the wrong string was kept when mapping to speed.

custom_components/tuya_local/devices/klarstein_ava_extractorhood.yaml

@@ -34,15 +34,15 @@ entities:
         type: string
         name: speed
         mapping:
-          - dps_val: "Off"
+          - dps_val: "off"
             value: 0
-          - dps_val: Low
+          - dps_val: low
             value: 25
-          - dps_val: Medium
+          - dps_val: middle
             value: 50
-          - dps_val: High
+          - dps_val: high
             value: 75
-          - dps_val: Strong
+          - dps_val: strong
             value: 100
   - entity: number
     translation_key: timer