[feature] Set jadx-gui default themes according to system light/dark mode

[skylot]

Describe your idea

Most systems now provide option to use dark mode and default light theme in jadx-gui fit badly.
Using https://github.com/Dansoftowner/jSystemThemeDetector library, it should be easy to detect current theme mode and apply matching themes by default.

Created by discussion in #2278 (comment)
Related to #1763.

[Real-Packet]

I think dark theme should be default. I think light theme has less users, and light theme's disadvantage is literally that it is light theme, which means that, to make it not hurt when you see a light mode GUI for the first time of the day at 6 AM or so, you need less light colors like yellow or blue

[Real-Packet]

This seems an easy thing, I'm implementing this on my feat/gui/theme/sync branch.