[React][Map] Install + use React Map GL component library

[mirandawang]

As we're adding more features to our map in React, it would be convenient to use a component library. React Map GL looks like a pretty good component library to use with Mapbox GL JS.
https://github.com/urbica/react-map-gl

Since most of Mapbox GL JS examples are for vanilla JS apps and not React, this makes it a bit easier to set things up in a React context. For example, Clustering!

Let's add the library to the app and port over the map component to the one that the library provides.

Acceptance Criteria

• React Map GL library is installed
• Mapbox Map JSX has been ported over to the React Map GL component