Filter all of generated links to include the snapshot UUID if present in the request

[westonruter]

When viewing the frontend of the site, clicking around should preserve the snapshot state as much as possible.

See https://github.com/xwp/wordpress-develop/pull/61/files#diff-4fb8a477f559bdfad2c1e6db6d1c8b06R887

[westonruter]

As part of this, we should remove all Admin Bar nodes that link the user into the admin. There could be an “Exit Preview” button that just strips out the UUID from the URL. Or whenever clicking an admin bar node that links you away from the preview, there could be a confirm prompt on click to alert them that they are leaving the snapshot preview. If they click cancel, then we could do event.preventDefault().

[westonruter]

Additionally, we can make use of sessionStorage to capture whether or not the user was in a snapshot frontend preview. If they end up landing on a new URL but didn't explicitly exit the preview, and yet the sessionStorage says that a specific snapshot UUID is being previewed, then there can be a prompt to restore the snapshot state. This would be a failsafe to recover from JS directing a user somewhere when the links aren't filtered.