Make KFontRequester consistent
Summary:
Make the KFontRequester widget consistent with the new font selection style in the Fonts KCM.
Test Plan: Open the GTK Application Style KCM.
Reviewers: Plasma, VDG, ngraham
Reviewed By: VDG, ngraham
Subscribers: VDG, kde-frameworks-devel, Plasma
Tags: Frameworks
Differential Revision: https://phabricator.kde.org/D19791