New feature: provide a way for consumers of this library to enable or disable nhsuk javascript shimming

[edwardhorsford]

This library includes reimplementations of nhsuk-frontend javascript. This is often needed as React works differently than how the native javascript expects.

If a team is using this library server side / pre-rendered, then they should be able to use the nhsuk-frontend javascript.

It would thus be good if this library provided a way to enable or disable the shimming, or otherwise know if it's rendered client or server side.