Add unified window focus opacity and dimming effects

compositor/src/overview.rs

@@ -1121,6 +1121,8 @@ mod tests {
         let scale = 0.97 + 0.03 * opacity.current;
         let id = WindowId(1);
         let presentation = WindowPresentation {
+            focus_alpha: 1.0,
+            dim: 0.0,
             id,
             bounds: AnimatedRect {
                 current: scaled_visual_rect(normal, scale),