Julia geometry ecosystem integration #35
Description
The geometry ecosystem is maturing, and we should take a fresh look at whether and how to integrate with it. Development seems to focus on geosciences but there are still generic methods and abstractions that could be useful to us. Probably the most utility for the least work would be to implement GeoInterface for our Polygon. Then we could at least use things like GeometryOps (e.g. for pure Julia clipping and simplification) or Rasters.jl (c.f. our homebrew gridpoints_in_polygon) with polygon-only geometries.