Inform user if a redirect exists when creating a new page
Given the following real life scenario:
root-page (/) - parent (/parent) - child (/parent/child)
When an editor moves "child" one level up:
root-page (/) - child (/child) - parent (/parent)
a redirect /parent/child => /child will be created.
If another editor then creates a page with the exact same title as before and at the same location as before, like so:
root-page (/) - child (/child) - parent (/parent) - child (/parent/child)
the created page /parent/child will still be redirected to /child.
The user should be informed that a redirect for the created slug already exists and if he wants to remove the redirect or adjust the slug. Or something like that.