Set the default cursor theme to breeze_cursors
Summary: Currently the cursor theme is not set by anything, so it's Adwaita by default.
Test Plan: New user account has "Breeze" as cursor theme in kde-gtk-config.
Reviewers: Plasma, ngraham
Reviewed By: ngraham
Subscribers: ngraham, broulik, plasma-devel
Tags: Plasma
Differential Revision: https://phabricator.kde.org/D17187