Change `:geom` and empty column names to `:geometry`

[rafaqz]

The default gdal geometry column name :geom is now in conflict with the GeoInterace.jl default of :geometry and julias tendency to spell things out. We have GeoInterface.geometrycolumns for packages, but its clunky for interactive use. Users want to just get the geometry column from a data frame in the normal dataframe syntax, with e.g. df.geometry and currently they are left guessing which package uses which name.

The fact that empty names are allowed is also a problem for users.

So I'm proposing we switch both :geom and empty names to :geometry.

https://github.com/JuliaGeo/GeoInterface.jl/issues/164

[alex-s-gardner]

Are we able to get a consensus on this? I think this would be good to standardize as early on as possible.

[rafaqz]

I think we just need a PR

[yeesian]

I've read the discussions etc, and am supportive of this. Can we make sure the implementation allows users to opt-in/out of it?

[rafaqz]

I guess we can have a geometrycolum keyword with :geometry as the default?

[alex-s-gardner]

So are we just adding an option to rename the geometry column in: https://github.com/yeesian/ArchGDAL.jl/blob/2e0a4a7f83398be54e19a0a1a3e6918b41f70cef/src/tables.jl#L1

[alex-s-gardner]

A decision was made to standardize geometry name in GeoDataFrames.jl... this issue can be closed.