c/sedona-proj: Implement ST_Transform and complete ST_SetSRID/ST_SetCrs for ItemCrs types

[paleolimbot]

In #410 we implemented ItemCrs types and a basic ST_SetSRID implementation; however, we still don't have all the combinations covered and ST_Transform is not implemented for ItemCrs yet. These are critical for converting back and forth!

[paleolimbot]

Also ST_Dump() is non-trivial!

[paleolimbot]

Also the functions that take an SRID as an extra parameter (e.g., ST_Point, ST_GeomFromWKT) aren't covered yet

[paleolimbot]

The first half of this is #531; the second is #547.