Fix/vqa style changes

[wtfluckey]

Goal

Styling changes from Visual QA, clean up colors and theme styling

Todos:

• [x] Align heading icon and item preview thumbnail
• [x] Align heading and item preview titles
• [x] Add spacing between item preview title and domain
• [x] Remove extra space under suggested tags
• [x] Update panel border-radius
• [x] Add icon to My List button, update styling
• [x] Delete old colors files
• [x] Clean up current color files, delete unused color variables, remove all dark theme specific styling