Make look of Font Management KCM UI more consistent
Summary:
Apply the KDE HIG and make tooltips, buttons and others more consistent and better looking.
Test Plan: Open the Font Management KCM.
Reviewers: Plasma, VDG, ngraham
Reviewed By: VDG, ngraham
Subscribers: ngraham, VDG, plasma-devel, Plasma
Tags: Plasma
Maniphest Tasks: T10273
Differential Revision: https://phabricator.kde.org/D19079