Add no-cache headers to receiver-ui responses

Introduce a `Transforms` section in `yarp.json` for the `receiver-ui` route to enforce a no-cache policy. This includes setting the following response headers for all responses:
- `Cache-Control`: `no-cache, no-store, must-revalidate`
- `Pragma`: `no-cache`
- `Expires`: `0`

These changes ensure that client-side caching is disabled for the `receiver-ui` route.

EnvelopeGenerator.API/yarp.json

@@ -39,7 +39,12 @@
         "Match": {
           "Path": "{**catch-all}",
           "Methods": [ "GET", "HEAD" ]
-        }
+        },
+        "Transforms": [
+          { "ResponseHeader": "Cache-Control", "Set": "no-cache, no-store, must-revalidate", "When": "Always" },
+          { "ResponseHeader": "Pragma", "Set": "no-cache", "When": "Always" },
+          { "ResponseHeader": "Expires", "Set": "0", "When": "Always" }
+        ]
       },
       "receiver-ui-annotation-fake": {
         "ClusterId": "receiver-ui",