Sprint 3: Create 'topper' component

Design at https://www.figma.com/design/DpS9o1LIG27rvzTqc13bcQ/Templates-%E2%80%93-wireframes?node-id=2179-13667

Requirements:

• Render site name (only set by Site Admin)
• Optional taxonomy for "Faculty of, School of, Department of".

Grey background for the topper.