Fix avatar picture aliasing and stretching in kickoff
Summary:
QML Image element has some smoothing when scaling an image by default but it's not enough and the picture still looks a bit pixelated. This patch fixes that.
Also while I was at it, I added keeping the aspect ratio, because no one likes their avatars stretched.
BUG: 369327
Test Plan:
Before:
After:
Reviewers: Plasma, mart
Reviewed By: Plasma, mart
Subscribers: davidedmundson, plasma-devel
Tags: Plasma
Differential Revision: https://phabricator.kde.org/D12469