Convert native-types points, polygons, etc to WKB

[m-mohr]

Thank you for this helpful library. It would be even more helpful to us to also have a conversion function that converts that native types (points etc) to WKB, e.g.

-- Convert back: GeoArrow native-typed struct → GEOMETRY (WKB)
SELECT st_geomfromgeoarrow('point', st_asgeoarrowpoint(ST_Point(30, 10)::GEOMETRY));

or similar

[am2222]

@m-mohr does this work?

-- Convert back: GeoArrow struct → GEOMETRY (WKT)
SELECT st_asText( st_geomfromgeoarrow(st_asgeoarrow(ST_Point(30, 10)::GEOMETRY)));

See on the shell

https://duckdb.org/community_extensions/extensions/duck_geoarrow

[m-mohr]

Not quite, that's pretty much what we do outside of duckdb now, but we need it generically for all types. Your proposal gets complicated very fast with all kinds of geometries, incl. 3D.

[am2222]

@m-mohr due to the similar complexities (different struct format) I ended up separating functions by their type (for point, line, polygon).
I can have a look at it in a couple of weeks but also if you want feel free to make a PR for it please and I will try to merge it!