Add confirmation banner when publishing without 2i
Add confirmation banner when publishing without 2i

This adds some guidance around when a publisher should publish without
2i when they hit the "Publish without 2i review" button. The
confirmation pop up follows the same pattern as some of the other
actions like 'delete' and 'revert to draft'.

The bulk of the text was copied from whitehall's 'Force publish' partial
here -> https://github.com/alphagov/whitehall/blob/master/app/views/admin/edition_workflow/_force_publish_modal.html.erb,
with a few words changed as there isn't a 'Force publish' concept in
collections-publisher.

Trello:
https://trello.com/c/NrZVDIlG/2018-3-alert-users-when-a-step-by-step-is-force-published-in-collections-publisher

alphagov/collections-publisher,alphagov/collections-publisher,alphagov/collections-publisher