R1:39cf0134728a

Add `objectPHID` keys to Harbormaster task schedulers

Summary:
Fixes T9816. It's currently hard to hunt down some particulars in the worker queue if things go awry in Harbormaster.

Supplement the queue with `objectPHID` keys so we can hunt tasks down more easily if the issues in T9816 continue.

Test Plan:
```
mysql> select * from worker_archivetask order by id desc limit 30;
+--------+------------------------------------------------+-----------------------------------+--------------+--------------+…