feat(rust/sedona-functions,c/sedona-geos): Implement geography kernels for structural transformations and accessors

[paleolimbot]

This PR adds geography matchers for a whack of functions whose output is the same for geometry and geography:

• ST_FlipCoordinates
• ST_Force2D, ST_Force3D, ST_Force3DM, ST_Force4D
• ST_GeometryN
• ST_InteriorRingN
• ST_Reverse
• ST_PointN
• ST_Boundary
• ST_LineMerge
• ST_Normalize
• ST_NRings
• ST_NumInteriorRings
• ST_NumPoints
• ST_Points

There's no implementation changes here, only updates to the matchers so that we get geography -> geography and geometry -> geometry.

Closes #819

[Copilot]

Pull request overview

This PR extends SedonaDB’s spatial function support so that a set of “mechanical” structural/accessor kernels accept geography inputs in addition to geometry, generally preserving the input type in the output. It also adds Python coverage for these geography transformations and updates GEOS-backed kernels to accept geography where appropriate.

Changes:

• Add geography-aware kernel matchers for multiple Rust sedona-functions UDFs that return the same type as their input.
• Update GEOS-backed C/Rust kernels (e.g., ST_Boundary, ST_LineMerge, ST_Normalize, ring/point counters) to accept geography inputs.
• Add a comprehensive Python test suite validating geography behavior for these mechanical transforms/accessors.

Reviewed changes

Copilot reviewed 15 out of 15 changed files in this pull request and generated 17 comments.

Show a summary per file

File	Description
rust/sedona-functions/src/st_start_point.rs	Adds separate geometry/geography kernels for start/end point accessors and updates tests.
rust/sedona-functions/src/st_reverse.rs	Adds geography matcher support for ST_Reverse and updates tests.
rust/sedona-functions/src/st_points.rs	Adds geography matcher support for ST_Points and updates tests.
rust/sedona-functions/src/st_pointn.rs	Adds geography matcher support for ST_PointN and updates tests.
rust/sedona-functions/src/st_interiorringn.rs	Adds geography matcher support for ST_InteriorRingN and updates tests.
rust/sedona-functions/src/st_geometryn.rs	Adds geography matcher support for ST_GeometryN and updates tests.
rust/sedona-functions/src/st_force_dim.rs	Extends force-dimension UDF tests to include geography.
rust/sedona-functions/src/st_flipcoordinates.rs	Adds geography matcher support for ST_FlipCoordinates and updates tests.
python/sedonadb/tests/geography/test_geog_mechanical_transforms.py	New Python tests validating geography behavior for multiple mechanical transforms/accessors.
c/sedona-geos/src/st_numpoints.rs	Allows ST_NumPoints to accept geography via is_geometry_or_geography() and expands tests.
c/sedona-geos/src/st_numinteriorrings.rs	Allows ST_NumInteriorRings to accept geography via is_geometry_or_geography() and expands tests.
c/sedona-geos/src/st_nrings.rs	Allows ST_NRings to accept geography via is_geometry_or_geography() and expands tests.
c/sedona-geos/src/st_normalize.rs	Adds separate geometry/geography kernels for ST_Normalize and updates tests.
c/sedona-geos/src/st_line_merge.rs	Adds separate geometry/geography kernels for ST_LineMerge and updates tests.
c/sedona-geos/src/st_boundary.rs	Adds separate geometry/geography kernels for ST_Boundary and updates tests.

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