[Feature Request] Native window decoration for GTK & QT

[iamkartiknayak]

Would it be feasible to implement this pop-os/libcosmic#464 (reference)?

Having native window decoration looked so good & now we have different window decoration for different technology which takes away the look & feel we desire from COSMIC. They reverted back saying it breaks GTK apps but if user wants to try it out on their own this feature would be great.