feat(encoding/mvt): support mvt marshal for GeometryCollection

[dadadamarine]

support collection marshaling in mvt.

• how? : (geometryGollection is intended to draw all the polygon in array) so just split geometryCollection to geometries
  • https://docs.mapbox.com/data/tilesets/guides/vector-tiles-standards/#winding-order
• testCase
  • similar with winding-order sample
  • 

[paulmach]

I agree with this PR. Why not support geometry collections by encoding each geometry separately. Makes sense. The only possible issue is that it's no longer a close mapping between geojson and mvt. if you go geojson -> mvt -> geojson the collection will become individual features. Not a big deal, but FYI.

However, this has nothing to do with winding-order. Winding-order refers to the individual rings within a single polygon. That is fully supported by the existing code.

[paulmach]

Thank you.