Icons of checkboxes are pixelated when device DPI is greater than 100%

[bleze]

1. The image below is taken on 4K / 200% monitor and scaled 10x. The red pixel is added to show that the pixels of the checkmark is 4x the size of a normal pixel. I'm guessing a bitmap/png is used for the graphics of checkmarks, rather than vector graphics.

125% scaling looks really bad, and can be tested/seen on a normal res monitor.

2. When focusing the property, the graphics turns from the bitmap to a QCheckBox which looks nice. This also have the side effect of checkbox being moved a few pixels as tried to show here;

3. Notice the blue focused rectangle is also drawn a bit misaligned.