[React 16] Use Error Boundaries

[eessex]

https://reactjs.org/blog/2017/07/26/error-handling-in-react-16.html

In React 15, a bug in a component would fail somewhat silently as console errors, but in 16 it brings down the entire tree and displays a WSOD (https://github.com/artsy/publishing/issues/285).

We need to implement the new <ErrorBoundary /> feature to contain these errors to select regions.

Potential sections to have boundaries:

• SectionContainer
• SectionList
• EditContent
• EditAdmin (and each drop-down panel)
• EditDisplay (and each drop-down panel)
• DisplayAdmin drop-down panels