Simplify hover detection

[victorlin]

preview

Description of proposed changes

• Use CSS hover selector instead of relying on a prop
• Limit the scope of ResourceLinkWrapper to just adding shift-click behavior

Related issue(s)

N/A, thought of this while working on #874

Checklist

• [x] Checks pass
• [x] Hover still changes text color on quick links and individual resources
• [x] Shift+click still opens modal for quick links and individual resources
• [x] ~Check if changes affect the resource index JSON revision~

[victorlin]

Tagged @jameshadfield as author of these lines and @genehack in case you're interested in front-end work related to #870