Update the SRID definition of the parquet raster standard

[jiayuasu]

As detailed in this issue #262 , we now have the projjson definition live on https://spatialreference.org/projjson_index.json. I think it is a good idea to update the Parquet Raster section since we now have a long-live and open definition of SRID.

@cholmes @paleolimbot @migurski should we allow authorities other than EPSG? I saw there are ESRI, .. and so on listed here https://spatialreference.org/projjson_index.json . Some of the ids are more than integers.

[paleolimbot]

should we allow authorities other than EPSG?

I think this is essential. A recentish bersion of PROJ's database has EPSG, ESRI, IAU_2015, IGNF, NKG, OGC (and the USER authority can be used to circumvent situations where the CRS can't be converted to an EPSG code, as happens rather frequently when importing arbitrary files into PostGIS).

[paleolimbot]

Another opinion here would be good, but I think this is a good approach. We want authority/code because in a lot of cases this will be more compact and in a lot of cases it will be hard-coded to a single string; however, in the generic case we'll be doing something like peeking into a GeoTIFF and parsing whatever CRS it contains (which may or may not resolve to an authority/code at a specified confidence level). I think we still want to handle that case rather than force implementations to error (particularly for the OutDB case).

[migurski]

Agreed with everything above, change looks good and we know we have support for non-EPSG authorities just be reading the stable URL at https://spatialreference.org/projjson_index.json

[jiayuasu]

@cholmes can you please review and merge this?