Release 1939

Trello card

https://trello.com/c/0JRIkXZE

Context

Migrate the cookie preferences form from the deprecated govuk_elements_form_builder to govuk_elements_form_builder

Changes proposed in this pull request

Update the localisation file and use the govuk_elements_form_builder helpers to render the form

Guidance to review

Visit the cookie page. Should look and behave exactly the same with before.