Improve handle loading semantics for tokenizers
Ref T7689. Fixes T7688. When there are a bunch of tokenizers with different values of the same object type (e.g. 5 tokenizers with users a, b, c, d, e) we currently issue 5 separate queries to load their handles.
Improve this behavior in the common case so we can usually batch these loads.
- In Maniphest, set the various search fields to different values.
- Used DarkConsole to examine query plan.
- Saw fewer queries after patch than before.
Reviewed By: btrahan
Differential Revision: https://secure.phabricator.com/D12261