Feature request: Interface scaling / font size

[asoftbird]

I'd like to have some kind of way to scale the interface up. On small monitors with high resolution, text is just too small to read comfortably (especially since I've not got the best eyesight).

Being able to specify a custom font would also be cool (so I can switch to a dyslexia-friendly font), but that's very much optional. Interface scale should get priority.

[veger]

This is much related to #321, as I mentioned in #321 (comment), the pixelsPerUnit depends on the system display settings (DPI I suppose), but adjusting this manually would scale the UI.

Having a setting to override the system default, would be fine/nice I guess. (I should not mess up the UI, if within reasonable limits)