add first pass at getMenuItemById

lib/browser/api/menu.js

@@ -189,6 +189,19 @@ Menu.prototype.closePopup = function (window) {
   }
 }
 
+Menu.prototype.getMenuItemById = function (items, id) {
+  if (items instanceof Menu) {
+    items = items.items;
+  }
+  let found = items.find(item => item.id === id) || false;
+  for(let i = 0, length = items.length; !found && i < length; i++) {
+    if (items[i].submenu) {
+      found = this.getMenuItemById(items[i].submenu, id);
+    }
+  }
+  return found;
+};
+
 Menu.prototype.append = function (item) {
   return this.insert(this.getItemCount(), item)
 }