[BUG] UI does not scale with high DPI

[Dr-Turtle]

Describe the bug
When using a high DPI monitor, the UI does not increase its scale

To Reproduce

1. Install and run on high DPI monitor

Expected behavior
UI to be larger relative to the monitor's DPI

Desktop:

• Occurs on both Arch Linux and KDE Neon (both using KDE and X11)
• both monitors tested on were 2560x1440p, one was 27", the other was 12.5"

Additional context
A workaround for Linux is to set GTK_SCALE (e.g. GTK_SCALE=2 ./pcgen.sh)

A simple fix for this would be to detect the user's DPI in pcgen.sh using xrandr (if installed) and setting GTK_SCALE from there (of course, a more robust solution would be preferred, but this would be better than nothing)