Set app-specific opacity

[m-obeid]

I currently have application blur on with the opacity set to 255, and my GTK theme handles the transparency. Some applications like VSCode don't use GTK, so it doesn't really work there. It would be nice to have the option to set custom opacity levels for each app, kind of like how on xorg, we were able to use xprop to set the opacity.

If I decrease opacity globally, that defeats the whole point of applying transparency to only the necessary parts.