Move x11/kde-applications/kcontacts to devel/kf5/kcontacts

Please find a attached kcontacts-5.68.0v0.tar.gz. kcontacts moved from
the KDE applications to the KDE framework. Changes:

- shared lib major bump
- EPOCH (18.12.0 to 5.68.0)
- @pkgpath x11/kde-applications/kcontacts

OK?