Implement ShapeSouce filter property

[ljukas]

The mapbox gl js supports filtering data before cluster processing on the source. This should be supported in the React native implementation as well via the ShapeSource component.

<ShapeSource url={dataUrl} clusterRadius={32} filter={['get', 'shouldCluster']} />

This would be very useful to off-load the data processing from the react javascript thread. With large data sets it is right now not optimal to first download the geoJson, then parse it in the react component and filter away the data you dont want to cluster before adding the data via the data prop.

Being able to filter it at this level would be very beneficial