Fix an issue where tokenizers can sort milestone results into the wrong query phase

Summary:
Fixes T11955. Currently, milestones have an internal name of "Parent (Milestone) ...".

This makes them look like they're prefix matches for "Parent", but they're actually prefix matches for "Milestone".

Reorder the names so that the internal name is "Milestone Parent ...".

Test Plan: Created a project "AAA" with milestone "BBB". Searched for "AAA", found "AAA" and milestone "AAA (BBB)".

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T11955

Differential Revision: https://secure.phabricator.com/D17013