Add Footer and Header component to Figma library

[pollecuttn]

To be done as and when needed?

[dana-saur]

• Header component has been added: https://www.figma.com/design/juZQR2wi2BsYG8TDH6R4uk/Wellcome-Collection-%E2%80%93-Styles-and-Component-Library-2023?node-id=2503-12071
• Footer still needs to be added