feat (avatto_wt20r_thermostat): add holiday temperature

Additional control found on WT20R-WH-3A-W
Details for this were actually in the cloud device spec.
This is the only one of the remaining additional controls that is documented
in the cloud spec and appears in the log.

Issue #3905

custom_components/tuya_local/devices/avatto_wt20r_thermostat.yaml

@@ -182,7 +182,54 @@ entities:
           - dps_val: null
             value: false
           - value: true
-# 102/103: Holiday temperature, but range unknown
+  - entity: number
+    name: Holiday temperature
+    category: config
+    icon: "mdi:island"
+    hidden: unavailable
+    dps:
+      - id: 102
+        type: integer
+        optional: true
+        name: value
+        range:
+          min: 1
+          max: 5
+        mapping:
+          - constraint: unit
+            conditions:
+              - dps_val: f
+                value_redirect: temp_f
+                range:
+                  min: 32
+                  max: 41
+      - id: 103
+        type: integer
+        optional: true
+        name: temp_f
+        range:
+          min: 32
+          max: 41
+      - id: 23
+        type: string
+        optional: true
+        name: unit
+        mapping:
+          - dps_val: f
+            value: F
+          - value: C
+      - id: 102
+        type: integer
+        optional: true
+        name: available
+        mapping:
+          - dps_val: null
+            value: true
+            constraint: temp_f
+            conditions:
+              - dps_val: null
+                value: false
+          - value: true
 # 104: sencer_c (sic) value "in", range unknown but probably same as 101?
 # 105/107: Home temperature, not sure if it is a setting or sensor
 # 112/113: Cook temperature, not sure what this is for (bad translation?)