R1:cbc71e75fae3

When queueing search index tasks, include the "objectPHID" in the task metadata

Summary:
Ref T13151. See PHI719. One minor hiccup in debugging the issue (which ended up being "revision has 100K comments") was that the `SearchWorker` did not show which object it was indexing.

Add `'objectPHID'` to the queue call so you can see which object is affected from the web UI.

Test Plan:
- Stopped daemons.
- Used `bin/search index D123 --background` to queue a search task.
- Viewed task details in web UI…