SQL: Switch JDBC driver to libs/geo objects for geo_points

[imotov]

Switches JDBC driver to use libs/geo objects when server returns a
geo_point. It also removes separate functions for geo points and geo
shapes, which should simplify developing of geo functions.

Closes #35767

[elasticmachine]

Pinging @elastic/es-analytics-geo

[elasticmachine]

Pinging @elastic/es-search

[imotov]

@elasticmachine run elasticsearch-ci/1

[costin]

If I understand correctly, this PR unifies the aswkt function across geo points and geo shape.
Is it correct to assume going forward that geo functions will support both types as input?

[costin]

LGTM.
I'd like @bpintea opinion as well to make sure the type format is supported on the ODBC side as well.
Besides WKT, are there any plans for other formats (WKB or geojson)?

[bpintea]

LGTM.
I'd like @bpintea opinion as well to make sure the type format is supported on the ODBC side as well.
Besides WKT, are there any plans for other formats (WKB or geojson)?

@costin I've added a comment to #39204 (comment).

JDBC allows shipping the defined private extensions along with the driver. In ODBC this concept doesn't exist: the interface is defined in the standard and any new extension is described through its characteristics, not by its format.

So, IMO we're free to pick whatever ways to encode the data, for as long as we can export it into a common format, either directly (by maybe using WKT/B or GeoJSON) or indirectly through function transformations.

[imotov]

Is it correct to assume going forward that geo functions will support both types as input?

Yes, and it will be easier now since we will have to write only one function. When I started implementing other functions earlier, having 2 sets of functions was a bit problematic.

Besides WKT, are there any plans for other formats (WKB or geojson)?

We are planning to eventually add ST_ functions that will support WKB and maybe other formats. However, I think it would make sense to stick with WKT to transport geo data between server and client for now. I think if we will switch to CBOR as a protocol, we can switch to WKB at that moment. For now, it makes little sense, I think.