WindowServer+Taskbar: Animate window frames on minimize/unminimize

We now show a quick window outline animation when going in/out of
minimized state. It's a simple 10 frame animation at 60fps, just to
give a visual cue of what's happening with the window.

The Taskbar sends over the corresponding button rect for each window
to the WindowServer using a new WM_SetWindowTaskbarRect message.

Note that when unminimizing, we still *show* the window right away,
and don't hold off until the animation has finished. This avoids
making the desktop feel slow/sluggish. :^)

Servers/WindowServer/WSWindow.cpp

@@ -103,6 +103,7 @@ void WSWindow::set_minimized(bool minimized)
     if (m_minimized == minimized)
         return;
     m_minimized = minimized;
+    start_minimize_animation();
     if (!minimized)
         request_update({ {}, size() });
     invalidate();