Introduce rating for assistant threads (#26780)

Release Notes:

- N/A

---------

Co-authored-by: Richard Feldman <oss@rtfeldman.com>
Co-authored-by: Agus Zubiaga <hi@aguz.me>

crates/collab/src/api/events.rs

@@ -660,6 +660,10 @@ fn for_snowflake(
                 e.event_type.clone(),
                 serde_json::to_value(&e.event_properties).unwrap(),
             ),
+            Event::AssistantThreadFeedback(e) => (
+                "Assistant Feedback".to_string(),
+                serde_json::to_value(&e).unwrap(),
+            ),
         };
 
         if let serde_json::Value::Object(ref mut map) = event_properties {