feat(news): rebuild the form of an article
The form lives at /admin/news/articles/new and /admin/news/articles/{id}/edit, the old addresses leading there. The name, the code and the two texts stand on the left; on the right the publication with the status the dates give, the section — which an article can now be moved to, its code having to be free there — and the tags, the fields for the search engines and, for a saved article, what it is beyond its form. A field the form does not accept is marked with its message. Saving stays on the form, "save and close" returns to the list of the section. The editor of the text is given the address it uploads pictures to, which the form left out.