* Fix issue #2758. Press Escape after a finished search to get back to Inbox
Use a keydown event when search bar is in focus to capture escape key press
* fix(search): Convert to ES2016
Summary: This improves performance of the search typeahead
Test Plan: Manual
Reviewers: bengotow
Reviewed By: bengotow
Differential Revision: https://phab.nylas.com/D3363