UX Improvement for Link Resource Creation

When an editor creates a new Link Resource, the system checks to see if that Link Resource already exists. If it does but belongs to a site that the editor does not have access to, the old behavior would redirect them to the Admin Dashboard and show a generic error message letting them know they don't have permissions. This was not very helpful. Now, the editor will be redirected to a page displaying information that explains how they can add the existing Link Resource to their Resource Group.