Add device icons for drones
Summary:
Add device icons for drones in 16px and 22px icons. Requested by @hein for his drone controlling endeavours.
They are named uav-quadcopter with uav as a symlink to uav-quadcopter, in case we add a uav with more rotors etc.
Test Plan:
Reviewers: VDG, hein, ngraham, rooty
Reviewed By: VDG, ngraham, rooty
Subscribers: ngraham, hein, kde-frameworks-devel
Tags: Frameworks
Differential Revision: https://phabricator.kde.org/D18901