Issues Relating to Search Bar

Problem/Motivation

1. On the news page, the search form field is missing a form label. We need at very least a screen reader one but we should probably add a visible label.
2. On the form submit button, the focus state outline doesn't have high enough contrast

Proposed resolution

1. Add a visible form label to the search field
2. Add outline-offset: 3px; to the focus state of the submit button