R1:d4a3706aeeb0

Move Repositories to SearchField

Summary: Ref T8441. Ref T7715. Internalizes `setQueryOrder()`. Removes `appendOrderFieldsToForm()`.

Test Plan: Used all Repository search fields.

Reviewers: btrahan

Reviewed By: btrahan

Subscribers: epriestley

Maniphest Tasks: T7715, T8441

Differential Revision: https://secure.phabricator.com/D13196