Support explicit Z/M coordinate values in WKT parsing for GeoPoint

[omricohenn]

#123111

This PR enhances the WKT parser to support explicit dimensionality declarations ("Z" and "M") as specified in the OGC Simple Features standard. Previously, Elasticsearch allowed a third dimension in WKT but did not explicitly support declaring that dimension as Z or M.

Changes

• Added support for "POINT Z" and "POINT M" syntax in the WKT parser
• Both formats require exactly three coordinates
• Added validation to ensure three coordinates are provided when Z or M is specified
• Added constants for Z and M in the Point class
• Added comprehensive test cases for all supported and unsupported formats
• Improved error messages for invalid input formats
• The _search API returns documents containing Z/M coordinates exactly as they were indexed, without any code modifications

Not supported

• The "ZM" dimensionality declaration (four dimensions) is not supported, as specified in the ticket.

[elasticsearchmachine]

Pinging @elastic/es-analytical-engine (Team:Analytics)

[iverase]

I was hoping to add support for Z/M for any type of geometry, not only points. Would that be possible?

[omricohenn]

@iverase sure, are you sure all the geometries should support it? I just couldn't find any official standard specifications that mention support for other geometries with Z/M. Could you please share if there are any?

[iverase]

The standard is here: https://www.ogc.org/publications/standard/sfa/