WL#14188: Ellipsoidal ST_Union

Affects: Server-8.0   —   Status: Complete

ST_Union currently only supports computations in Cartesian spatial reference systems (SRSs). This WL refactors the current implementation for Cartesian SRSs, and adds support for geograhic SRSs.

ST_Union(geometry, geometry) takes two geometries, and returns their union geometry.

The function is implemented for all geometries in all spatial reference systems, both Cartesian and geographic.