deposit: new submission button on submission completed

Signed-off-by: Javier Martin Montull <javier.martin.montull@cern.ch>
deposit: template changes

* Adds new submission button to form.

* More responsive form fields.

* Tip at the top of the form.

Signed-off-by: Javier Martin Montull <javier.martin.montull@cern.ch>