Change Highlight to ButtonFocus
Summary: Changed Highlight to Button focus so that these SVGs wouldn't use the same color as the selection background.
Reviewers: VDG, Plasma, Breeze, ngraham
Reviewed By: VDG, Breeze, ngraham
Subscribers: ngraham, kde-frameworks-devel
Tags: Frameworks
Differential Revision: https://phabricator.kde.org/D22670