Forms 2.0: make it possible to add a text area after the submit button (Without JS)

With the GDPR, we need more flexibility in how we ordinate things in forms. adding fields below the progressive profiling is covered but we also need to have the possibility to add a text area below the submit button without needing to code some JS.

Typical use case if to be able to add legal mentions (GDPR information for instance) after the button on embedded forms and Marketo LP forms all the same.

-Greg