feat (sh07_sprinkler_controller): make schedules available

As described on #2143, missing dp 107 is for the schedule, which is
too complex a format to support directly, but we can expose it as a
text entity to allow layering a decoding/encoding layer on top of.

Based on rude complaint on discussion #4596

custom_components/tuya_local/devices/sh07_sprinkler_controller.yaml

@@ -102,3 +102,13 @@ entities:
         name: valve
         type: boolean
         optional: true
+  - entity: text
+    name: Schedules
+    category: config
+    icon: "mdi:calendar-clock"
+    hidden: true
+    dps:
+      - id: 107
+        type: base64
+        optional: true
+        name: value