Make application transparency opt-in (#14253)

* Make application transparency opt-in

* Use the transparency helper for Kanagawa

* Address transparency review findings

* Toggle transparency for opaque windows too

default/hypr/apps/windows-vm.lua

@@ -1,5 +0,0 @@
--- Keep the Windows VM display opaque instead of applying the default window opacity.
-o.window({ class = "^xfreerdp$", title = "^Windows VM - Omarchy$" }, {
-  tag = "-default-opacity",
-  opacity = "1 1",
-})