KF5 port: remove KF5::KDELibs4Support

Summary: last patch (only 5, not 7 patches needed) to remove kdelibs4support from frameworks branch

Test Plan: this one removes the last pieces from CMakeLists.txt - only works after the other 4. Still compiles, but now kdelibs4support - free :)

Reviewers: #kde_games, ltoscano

Reviewed By: ltoscano

Subscribers: ltoscano, #kde_games

Differential Revision: https://phabricator.kde.org/D7420