Fixed FFDec appearing blurry on macOS

[psy-guy]

Makes the application look clearer overall on macOS (see images)

Before:

After:

[jindrapetrik]

It's easy to set uiscale to 2, but will this work in Linux aswell? We use this file (ffdec.sh) for both Mac and Linux. And I think setting to 2 on nonretina displays will just make the UI 2 times bigger. So maybe make somehow separate file for retina displays (?). Or maybe we can set the variable somehow in the app itself. I will think about it...

[TheKodeToad]

This is what happens on Linux (Java 17).

Before:

After:

[jindrapetrik]

In nightly 2246, you can set the "UI scale factor" value in Advanced settings (application exit after that is required).
Set it to 2.0 on retina displays.
I did a little investigation and there is no reliable way to tell that retina is used in Java automatically.
So you need to manually set the config.