Add the "Back to site" link in the breadcrumb

There was agreement on using Gin's proposal for now: a link before the breadcrumb, with an arrow pointing left and right spacing + a vertical line separating them. This is going to be the fastest way to test is the place is correct on the user tests. Attaching an image with it and updating the issue summary.

Working on this now!

Hey @ckrina, can you please send me an icon for the back arrow? Or can I pull from Figma somewhere?

Merged!

Automatically closed - issue fixed for 2 weeks with no activity.