R1:4d175ac70970

Simplify how tag lists manage their handles

Summary: Fixes T11493. This code is a little bit weird/clever, simplify it so that we always cast the handles to an array early on.

Test Plan: {F1767668}

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T11493

Differential Revision: https://secure.phabricator.com/D16422