plus/minus icon interaction is incorrect

[johnnyporkchops]

In smaller screen sizes, (when the menu becomes accessible via the hamburger icon) the plus/minus icons do not work correctly.

@jcarroll is attempting to make the menu html structure match fec-cms by removing the use of handlebars templates and using included html partials--work in progress.

This is related to an fec-cms issue to solve the misleading icon cues on the mega menu:
fecgov/fec-cms#2172

[JonellaCulmer]

It appears that only on a desktop browser window, where you manually shrink the size of the screen to show the mobile view, that users can't close a submenu.

When you're on an actual mobile device, clicking anywhere on the menu titles will close the submenu.