Damn it, I think I made this mistake already once. Because also user provided URLs can be bookmarked where
e.g. the share name is written in lower case although it is capitalized, we cannot use QUrl::matches() here,
because it does not allow for case insensitive comparison. I added a comment so that I do not forget anymore...

In addition, the argument of Smb4KBookmarkHandler::bookmarksList(QString) was renamed so that is is clearer
what it stands for.