Draw main search border around button also
Summary: Extends the focus highlight around the button on main search bar as well as input.
Test Plan: reviewed on desktop and mobile breakpoints. did a search. woo.
Reviewers: btrahan, epriestley
Reviewed By: epriestley
Subscribers: Korvin, epriestley
Differential Revision: https://secure.phabricator.com/D12364