R1:7be02e659a02

Make typeahead results more structured

Summary: Get rid of this positional array garbage.

Test Plan: Used typeaheads in menu, herald, maniphest, differential, repository/projects.

Reviewers: vrana, btrahan

Reviewed By: vrana

CC: aran

Maniphest Tasks: T1569

Differential Revision: https://secure.phabricator.com/D3116