feat: Status message

[holloway]

Requirements:

• show a status message on all pages to users
• doesn't require JavaScript
• doesn't pollute Cloudflare cache with status messages (ie status messages can't be inline in the template, the browser has to compose the page)

This approach uses a non-JS fallback via <noscript><iframe src=></iframe></noscript>, and for JS users there's JS + API to show a message.

There isn't any design applied yet to either approach. The UX of this has not been decided.