remove {sf} as a dependency

[JosiahParry]

Is your feature request related to a problem? Please describe.

{sf} is a massive dependency. It would be nice to be able to migrate off of it. An initial migration can still return an sf object but only by applying the class and ensuring the structure is correct. This is like arcgisplaces.

We can use wk in place of sf for things like st_crs()

Another alternative would be to use geoarrow as an optional output format which can be used when sf isn't present and can put sf in suggests. But that feels less good.