ACMS-000: Fixing border focus issue on menu links.

[aellison]

Motivation
Gold border around focused links causes link to grow larger than container.
Fixes #NNN

Proposed changes
Increase specificity of CSS. Apply "display: block" property only focusable items with a role property of "link".

Alternatives considered
Switching the display of link focus border flex properties. Would have had larger impact that would be hard to test for.

Testing steps

• Navigate to any page. Use the tab key to add focus to main nav links. Ensure that the link doesn't jump around.
• Navigate to /search page and search for term that yields results. Tab through facets and ensure that gold border wraps focusable links.

Merge requirements

• _Bug
• Manual testing by a reviewer