Implement the Fluent Design Acrylic effect into Chatterino

[Void48]

I think this would definitely make Chatterino feel more modern and fresh if its possible 👍

Here are some links that should help with implementing this:
https://github.com/Extrimis/Win32-Acrylic-Effect
https://stackoverflow.com/questions/57626018/how-to-get-a-blurred-translucent-qml-window-similar-to-fluent-design-guidelines
https://forum.qt.io/topic/51055/enableblurbehindwindow-not-working

[Mm2PL]

I can see this being an option however it needs #1618. I would accept a PR for this but it would be best if this wasn't a windows only thing but a crossplatform thing instead.