[Feat] ImageMapType Support

Target Use Case

Add the ability to add tile layers. For example, a component that could be used to consume the new Air Quality heat map tile endpoint. Currently, I am not sure what the recommended best practice for tile layers would be with this library, perhaps using the DeckGL overlay and adding via DeckGL overlay's layers prop?

Proposal

I'm thinking the </Map /> component could accept <TileLayer /> components as children. TileLayer component would accept props similar to its current API: getTileUrl, opacity, getTileSize, etc.

import {APIProvider, Map, TileLayer } from '@vis.gl/react-google-maps';

function App() {
  const position = {lat: 53.54992, lng: 10.00678};

  return (
    <APIProvider apiKey={'YOUR API KEY HERE'}>
      <Map center={position} zoom={10}>
        <TileLayer getTileUrl={(coord, zoom) => `https://airquality.googleapis.com/v1/mapTypes/US_AQI/heatmapTiles/${zoom}/${coord.x}/${coord.y}key=${API_KEY}` 
    }  />
      </Map>
    </APIProvider>
  );
}

export default App;

Start by reviewing the Map component's child handling and the Google Maps ImageMapType API to determine how tile layers should be integrated. Define the TileLayer props described in the proposal, support it as a Map child, and verify that a configured tile URL, opacity, and tile size produce the requested overlay.