Use KQuickCharts to render notification timeout as a circular progress bar

Summary:
This uses the new KQuickCharts framework to render the notification timeout bar as a small
circular progress bar, around the close button.

Video:

{F7818131}

Test Plan:
notify-send -t 15000 test will first show a notification with no indicator, then once the
timeout gets to 10s or less it will show a decreasing circular progress bar.

Reviewers: #plasma, broulik, ngraham

Reviewed By: #plasma, broulik, ngraham

Subscribers: ngraham, plasma-devel

Tags: #plasma

Differential Revision: https://phabricator.kde.org/D25993