python top-level function API

[kylebarron]

This is just a proof of concept, only for area. It's annoying how verbose the implementation is, so I want to ideate on that a bit more.

It works!

import pyarrow as pa
import shapely
import pandas as pd
import geopandas as gpd
from geoarrow.rust.core import WKBArray

gdf = gpd.read_file(gpd.datasets.get_path('nybb'))
large_gdf = pd.concat([gdf] * 1000)
wkb = shapely.to_wkb(large_gdf['geometry'])

pa_wkb_arr = pa.array(wkb)
rust_wkb_arr = WKBArray.from_arrow(pa_wkb_arr)
rust_multi_polygon_arr = rust_wkb_arr.to_multi_polygon_array()
area1 = rust_multi_polygon_arr.area()

from geoarrow.rust.core import area
area2 = area(rust_multi_polygon_arr)

Closes #266. For geoarrow/geoarrow-python#38