feat: add control center widget

widgets/control-center/notification-list.tsx

@@ -0,0 +1,12 @@
+import { Gtk } from "ags/gtk4";
+
+export const NotificationList = () => {
+  const { VERTICAL } = Gtk.Orientation;
+
+  return (
+    <box vexpand orientation={VERTICAL} spacing={20}>
+      <label label="Notifications" />
+      <box vexpand cssClasses={["pill"]}></box>
+    </box>
+  );
+};