Centralize menu button coordinate logic and replace popupwindows with dropdownmenu.

modules/menus/calendar/index.js

@@ -1,14 +1,12 @@
-import PopupWindow from "../PopupWindow.js";
+import DropdownMenu from "../DropdownMenu.js";
 import { TimeWidget } from "./time/index.js";
 import { CalendarWidget } from "./calendar.js";
 import { WeatherWidget } from "./weather/index.js";
 
 export default () => {
-  return PopupWindow({
+  return DropdownMenu({
     name: "calendarmenu",
-    visible: false,
     transition: "crossfade",
-    layout: "top-right",
     child: Widget.Box({
       class_name: "calendar-menu-content",
       css: "padding: 1px; margin: -1px;",