EuiSearchBar controlled input breaks in React 16.4

[bevacqua]

You can verify with the docs as we just have with @chandlerprall

[chandlerprall]

16.4 fixed a bug around getDerivedStateFromProps where that function is now called after a component's own setState, which is interrupting the search bar's flow to notify the controlling parent of a change.

@bevacqua also discovered that a controlled search bar blows up if provided an invalid query.