Add a podcast cover image to the audio page

[oliverabrahams]

What does this change?

Why?

Migrating the audio page from FE to DCR.

This PR has a slight change in the Props for the <Picture/> component. It now allows passing of the image widths directly. imageWidths: [ImageWidthType, ...ImageWidthType[]]; this is only allowed when the role passed to the <Picture/> is "custom" otherwise it is imageWidths: never

Screenshots