Cookie consent translation

The cookie pop-up banner is currently in English only, and loaded from an external [static dependency](https://github.com/okfn/a/tree/master/a/html/oki/consent) which does not make it possible to translate the text. This is not only important messaging, we should also offer a [no tracking choice](https://www.cookiechoices.org/). I would suggest switching to a more robust consent plugin.