Add some sort of sort to Emoji Autocomplete

Summary: Ref T12139. Adds sorting by shortname. Also I sorted everything else. No reason. It didn't help

Test Plan: `:star`

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: Korvin

Maniphest Tasks: T12139

Differential Revision: https://secure.phabricator.com/D17246

Author: Chad Little