"Make a box" should be in menu

[bfirsh]

Problem

There should be should be a "Make a box" link in the menu.

Proposed solution

The dialog is currently contained within the dashboard page, so it cannot be opened from anywhere else.

The dialog should instead be global - perhaps in App.js. The open state of whether it is open or not should probably be stored in Redux. That way, anything in the application that wants to open the make a box dialog can just fire off a Redux action.

[Continuities]

[TA] On it.

[HaGuesto]

@jamescrowley I think we should close this issue and discuss next meeting how our menu should look like.

I created a new issue for it #505