[#79509870] Move and remove a module when creating

This works in a similar way to adding a module. The module is removed from the pending_dashboard in the session and the form is redisplayed.

This is #59 rebased on master.
Can we flash the title? It's hard to see which one you have just updated on the list page. I know it was previously doing slug so I'm happy to change this in a separate pull request.