Add icons to Kicker/Kickoff context menu items and correct capitalizations
Summary:
Test Plan: Open Kicker and open the context menu for a menu item.
Reviewers: Plasma, VDG, ngraham
Reviewed By: VDG, ngraham
Subscribers: VDG, plasma-devel, Plasma
Tags: Plasma
Differential Revision: https://phabricator.kde.org/D23793