enabled content_moderation module and created editorial workflow for all content pages

The editorial workflow adds the option to set a content page to draft without unpublishing the page. view_unpublished is still required to see actual unpublished content and revision history.

Note: this will also add the Content Moderation tab to permissions for more granular user control. As of now, all content editors will be able to set content pages to draft, published or archived status. If collaboration with external editors is desired in the future, a new role with fewer permissions could be created.