Geospatial: polygon conforms to standard

[sync-by-unito]

Make sure that Polygons are conforming to the same standard that the MongoDB server uses. This discrepancy is about how many points are allowed minimum (3 or 4), and if the first point must be the same as the last or if they are implied to be connected. Also check if the orientation is CCW or CW. We may need to transform the data before passing it to s2 for calculations.