RGI 7.0 shapefile geometries are stored as 3D polygons

[fmaussion]

RGI version
RGI v7.0

Describe the issue
GLIMS provides the geometries as 3D polygons, and this is then carried over to the RGI files. Many shapefile readers do not have any problem with 3D geometries, but some do.

Expected outcome
RGI files should not have a z dimension.

Suggested solution
The files can be converted with python with:

import geopandas as gpd
df = gpd.read_file('RGI2000-v7.0-G-12_caucasus_middle_east')
df['geometry'] = gpd.GeoSeries.from_wkb(df.to_wkb(output_dimension=2).geometry)
df.to_file('RGI2000-v7.0-G-12_caucasus_middle_east_noz/RGI2000-v7.0-G-12_caucasus_middle_east.shp')

I'll run this on all of RGI 7.0 and share the files somewhere. This will be solved in RGI 7.1.