enable top menu items to be changed and customized in the CMS admin interface

[ghwood]

Currently only some "secondary" top menu elements are editable via the www.ietf.org/admin->settings web interface.

It should be possible to add/remove/edit secondary top menu items more generally, including adding new menu elements and links, and having drop-down options, similar to the "Tools" secondary top menu item, as shown in the screenshot.

[kesara]

The current website has two sets of top-level menus:

• Primary top-level menu
• Secondary top-level menu

These two menu sets are responsive and have different styling.

This ticket is only to change Secondary top-level menu items.

Only Tools menu in secondary top-level menu items are fully customizable now.
admin -> settings -> secondary menu

The requirements of this ticket are:

• Ability to add, remove, and reorder secondary menu items from admin -> settings -> secondary menu
• Ability to add child menu items into any secondary menu item. (Similar to Tools menu)
• If there are child menu items in a secondary menu item, that menu will show up as a dropdown similar to the current Tools menu.
• If the secondary menu item doesn't have any child menu items, that menu will show as a link similar to Contact or News & Blog.

• Changes must preserve existing responsive design and stylings.

[kesara]

Available in production.