Remove unnecessary qmldirs that were exposing private APIs

I was sifting through api.kde.org, when I noticed there were some strange entries:

Then I realized some of these were actually private types, that were accidentally exposed through some extra qmldirs. Since they're just used for module declarations, they should be safe to remove. Some of the private aliases are changed to match the others.

Recommended to cherry-pick to KF5 so that current documentation can be updated.