Add shadow to Hour's hand

Summary:
BUG: 396612
Depends on D18288
Hour hand did not had shadow.
Now it has.

Test Plan: Add new analog clock widget from "Add widget" on right click context menu

Reviewers: mart, hein, VDG, ngraham, davidedmundson

Reviewed By: VDG, ngraham, davidedmundson

Subscribers: ndavis, abetts, ngraham, davidedmundson, plasma-devel

Tags: Plasma

Differential Revision: https://phabricator.kde.org/D17751