Set the size of the marching ants based on the dpi of the screen
This also handles moving the Krita window from screen to screen and interactively changing the resolution of the screen.
Notes:
- we might need to tweak the scaling factor, or figure out a way to decide what the idea ant size in mm would be and then calculate that based on the physical dpi of the screen.
- ideally all other KisPaintingTweaks::initAntsPen users should use this system, which should be generalized. I didn't figure that out
- the reporter of the original bug also wants the width of the line to increase, but since these are cosmetic pens, that doesn't work. Making the pens non-cosmetic gives really weird results.
Edited by Halla Rempt