v1.0.0a2: support GeometryCollection and GeoJSON feature collections

• FEATURE: Added support for Shapely GeometryCollection geometries;
• FEATURE: Added support for GeoJSon feature collections model that represents
  a GeoJSON feature collection and serialize it to a GeoJSON feature collection;
• REFACTOR: Changed the GeoJSON geometry models from TypeAlias to sub classes of the corresponding
  base-models. This gives a better documentation in the API. This has no effects on the functionality
  of the package.
• BUGFIX: Changed wkt.dumps and wkt.loads to respectively shapely.to_wkt and
  shapely.wkt.loads;
• BUGFIX: Fixed a bug where the class property ParentDataModel was not being set when the
  a sub-class of GeoJsonFeatureBaseModel was created. This prohibited the correct
  serialization of the Feature Collection;