app/internal/wm: use Option method to initialize windows

Added (*w.window).Option methods to the backends and use them for setting the initial options passed into NewWindow.

Signed-off-by: pierre <pierre.curto@gmail.com>

app/internal/wm/window.go

@@ -74,6 +74,9 @@ type Driver interface {
 	// WriteClipboard requests a clipboard write.
 	WriteClipboard(s string)
 
+	// Option processes option changes.
+	Option(opts *Options)
+
 	// SetCursor updates the current cursor to name.
 	SetCursor(name pointer.CursorName)