Search Typeahead - make exact matches show up first

Summary: Fixes T6102. Give "priority" treatment to strings that are exact matches.

Test Plan:
made a bunch of projects with the word project in them including "Project". before patch, "Project" wouldn't even show up if I typed "Project" - now its the second result right after the application "Projects".

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: Korvin, epriestley

Maniphest Tasks: T6102

Differential Revision: https://secure.phabricator.com/D10867