Ensure features property is typed as MapGeoJSONFeature[] on MapLayerMouseEvent and MapLayerTouchEvent.

[parkerziegler]

Currently, MapLayerMouseEvent and MapLayerTouchEvent are typed with their features property as GeoJSON.Feature[]. However, the features returned on either of these events are MapGeoJSONFeatures; they contain the additional properties of that interface (e.g., layer, source, sourceLayer, and state). In addition, it appears the unit tests already cast features returned on MapLayerMouseEvents to MapGeoJSONFeature[]; see here for an example. This PR just corrects the types!

Looking through the CHANGELOG, it appears MapGeoJSONFeature is a fairly new addition (2.1.8-pre.2), so I think this may just be on spot where the types got missed!

Launch Checklist

• Confirm your changes do not include backports from Mapbox projects (unless with compliant license) - if you are not sure about this, please ask!
• Briefly describe the changes in this PR.
• Document any changes to public APIs.
  • While these types are part of the TypeScript public API, they are not core to the library API (nor currently documented on the docs site).
• Add an entry to CHANGELOG.md under the ## main section.

[HarelM]

Thanks for taking the time to fix this!
The migration from flow to typescript contained a lot of changes, so it makes sense this was missed.