Remove KUrl from autorefresh, dirfilter, domtreeview and fsview plugins

Summary:
Remove use of KUrl from plugins

This is the first step in the long road to remove use of KDELibs4Support

Plugins which currently aren't compiled (for example, UAChanger or
AdBlock) haven't been changed

Test Plan: check that konqueror and its plugins compile

Reviewers: dfaure

Reviewed By: dfaure

Differential Revision: https://phabricator.kde.org/D14979