[dict] Modernize configuration window
Summary:
This patch bumps dictionary's settings QtQuickControls from version 1 to 2.
It also changes the configuration category's icon to match the applet's one.
NOTE: It would be good if we could get keyboard navigation to work, it doesn't seem to want to be doing it now.
Test Plan:
Before:
After:
Reviewers: dfaure, ngraham, VDG, Plasma, davidedmundson, mart
Reviewed By: ngraham, VDG, Plasma, davidedmundson, mart
Subscribers: GB_2, mart, broulik, plasma-devel
Tags: Plasma
Maniphest Tasks: T10586
Differential Revision: https://phabricator.kde.org/D20797