Using WKB for geometries

[nhungoc1508]

Hello, thank you for the fantastic work!

I see that in geometry-related functions, you're using geometry_to_gserialized() to convert from Shapely's geometry to GSERIALIZED. This function uses wkt.dumps() and geom_in() to obtain the GSERIALIZED object. Would you consider using wkb.dumps() and geo_from_ewkb() instead? I think handling the binary format gives you a bit of a speed boost over the string-based approach.