Create "Draft" namespace on the English Wikipedia

Also set the new namespace(s) to be "noindex,nofollow" and grant all users
(specifically anons) the ability to create pages in the "Draft" namespace.

Add VisualEditor to the new namespace (applies for opt-in users currently).

Remove Labs testing for this change.

Bug: 57569
Co-Author: Matthew Flaschen <mflaschen@wikimedia.org>
Change-Id: Ib56f1085eea106de6767162e77614e36d2a505ca