Cleaner only shows cached delete locations

[lemora]

ToDo: Cleaner should report all delete locations when queried, not just the cached ones.

Originally, the hsm component of the cleaner cell would cache all delete locations, which could result in running out of memory. The admin command to list delete requests (requests ls) reports the requests which are currently cached, which, after limiting the cached delete locations to a configurable number, is no longer the entirety of delete requests contained in the trash table.