- Provide digikamalbums:// URLs to KIO::del
This reliably removes the entries from the database.
It usually worked before because the KDirWatch would trigger a rescan,
but under certain conditions (saved as and then deleted immediately) it did not work.

- In AlbumIconView, move the KIconEffect::visualActivate to the click action. This is more homogenous: It is now associated with a click on an icon, regardless if for preview or image editor.