fix: listen for google maps key events on document, not map container

[morehawes]

Proposed fix for #129.

Google Maps was not picking up keyboard events ("keyup"/"keydown"). This change listens for keyboard events on the entire document, instead of the map container.

This means keyboard deletion is now working for Google Maps.

The only unintended consequence that I can think of is if there are multiple Terra Draw instances, both would respond to these events.

For example, in the development/ app if you have a Feature selected in Google Maps and then switch to another Map and select/delete a feature it will also pick up the keyboard event and delete it from the GM map also.

[morehawes]

My bad. The Jest testing environment is set to node so is squawking:

The error below may be caused by using the wrong test environment, see https://jestjs.io/docs/configuration#testenvironment-string.
    Consider using the "jsdom" test environment.

    ReferenceError: document is not defined

Further problems with the test expecting HTMLDivElement when I make that change, so instead of changing any tests I will pause on this for now.