The GIS function ST_Collect takes as input multiple geometries and
returns the aggregation of the distinct geometry arguments.
The resulting value type is choosen using the following policy:
  - If all arguments are Point values, the result is a MultiPoint value.
  - If all arguments are LineString values, the result is a
    MultiLineString value.
  - If all arguments are Polygon values, the result is a MultiPolygon
    value.
  - Otherwise, the result is a GeometryCollection value.

If there are multiple geometry arguments and those arguments are in the
same SRS, the return value is in that SRS. If those arguments are not
in the same SRS, an ER_GIS_DIFFERENT_SRIDS_AGGREGATION error occurs.

Author: StefanoPetrilli <stefanop_1999@hotmail.it>
Co-authored-by: Torje Digernes <torje.digernes@oracle.com>
Co-authored-by: Steinar H. Gunderson <steinar.gunderson@oracle.com>