If we have multiple defaulting plugins, then we should zonk in between them

In #23821 (closed) we discovered that running defaulting plugins can interfere with the built-in defaulting mechanism. This was fixed in !11084 (closed) by re-zonking the wanteds between the plugins and the built-in defaulting. However, as @sheaf noted in #23821 (comment 521484), we also have the same issue between defaulting plugins when more than one is installed. So here we move that re-zonking to happen after each plugin call that made any progress.