builtins: implement ST_ForceCollection

[erikgrinaker]

Some test cases deviate from PostGIS due to a bug in the WKT encoder (see #53632). The behavior of ST_ForceCollection is correct, but the WKT output does not accurately represent the resulting geometry. Not sure if we should wait for the upstream fix or merge this as-is.

Release justification: low risk, high benefit changes to existing functionality

Release note (sql change): Implement the geometry builtin
ST_ForceCollection.

Closes #48934.

[blathers-crl]

Thank you for contributing to CockroachDB. Please ensure you have followed the guidelines for creating a PR.

My owl senses detect your PR is good for review. Please keep an eye out for any test failures in CI.

I have added a few people who may be able to assist in reviewing:

• @otan (commented on geo: SpatialObjectToWKT() omits empty shapes in collections  #53632, author of geo/geomfn: implement ST_ForceCollection({geometry}) #48934)

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[cockroach-teamcity]

This change is 

[otan]

Let's wait for the upstream changes (I'll patch GEOS with the relevant fix), should be able to do this Monday!

[blathers-crl]

Thank you for updating your pull request.

My owl senses detect your PR is good for review. Please keep an eye out for any test failures in CI.

_{🦉 Hoot! I am a Blathers, a bot for CockroachDB. My owner is otan.}

[erikgrinaker]

Thanks for the dep bumps and fixes! Rebased onto master and updated tests.

[otan]

bors r+

[craig]

Canceled.

[erikgrinaker]

Rebased to fix merge conflicts.

[otan]

bors r+

[craig]

Build succeeded:

• GitHub CI (Cockroach)