FeatureCollection.fromJson() should also accept a 'Reader' parameter

Currently a FeatureCollection can not be instantiated from a Reader.
The only function provided requires a String in JSON format as can be seen here.

Such approach is inefficient when reading larger files since the entire file content has to be read and stored in memory before it can be transformed into a FeatureCollection.
If a FeatureCollection could be instantiated from a Reader aswell, only parts of the read file would have to be stored in memory which makes this the more desirable approach in the presented situation.

As the used GSON library already enables the use of a Reader instead of a String, the implementation would be very simple and could look like this:

@Nullable
public static FeatureCollection fromJson(@NonNull Reader reader) { 
  GsonBuilder gson = new GsonBuilder();
  gson.registerTypeAdapterFactory(GeoJsonAdapterFactory.create());
  gson.registerTypeAdapterFactory(GeometryAdapterFactory.create());
  return gson.create().fromJson(reader, FeatureCollection.class);
}

Đọc services-geojson/src/main/java/com/mapbox/geojson/FeatureCollection.java và entry point fromJson(String) hiện có. Thêm overload cho Reader bằng thiết lập Gson adapter đã nêu, sau đó chạy các bài kiểm thử liên quan của dự án và xác nhận rằng đầu vào Reader tạo ra một FeatureCollection mà không thay đổi hành vi hiện có của String.