[GH-3203] Preserve Geography coordinates and polygon ring semantics

[jiayuasu]

Did you read the Contributor Guide?

• Yes, I have read the Contributor Rules and Contributor Development Guide.

Is this PR related to a ticket?

• Yes, and the PR name follows the format [GH-XXX] my subject. Closes [BUG]: WKBGeography object rendering truncates coordinates #3203.

What changes were proposed in this PR?

• Render default WKBGeography.toString() and toEWKT() output from the authoritative stored WKB/JTS representation.
• Preserve exact coordinates, positive SRIDs, repeated LineString vertices, and empty polygons without an unnecessary S2 round trip.
• Build ST_GeomToGeography values directly from JTS WKB so conversion does not introduce longitude/latitude drift.
• Interpret polygon rings by their simple-features roles in all public Geography readers: the first ring is the shell and subsequent rings are holes, regardless of input winding.
• Preserve the submitted WKB and coordinate order for structural output while normalizing only the S2-facing traversal used by spherical predicates.
• Keep the explicit PrecisionModel text overloads on the S2 writer for callers that request precision-controlled output.
• Add an internal orientation-preserving shape conversion for raster distance predicates. This keeps reprojected raster footprints directed when they cover more than a hemisphere without changing public Geography semantics.

Spark DataFrame display now agrees with WKB-backed structural functions such as ST_AsText. Spark and Flink use the same Geography reader and predicate behavior.

Polygon semantics

Public Geography polygon shells are normalized to an area of at most one hemisphere. A shell intended to represent more than half the sphere is interpreted as its complement, and reversing its coordinate sequence does not select the larger region. Structural WKB/WKT remains unchanged.

Raster distance predicates are the deliberate exception. Their internal conversion preserves the orientation of a reprojected raster footprint because that directed footprint may legitimately cover more than half the sphere.

Performance

The single-ring WkbS2Shape path computes orientation and origin containment without an additional full edge scan. In a local warmed-up benchmark using a 25,000-vertex polygon:

• normalized shape construction: 1.406 ms, compared with 1.514 ms before the fast path;
• ShapeIndex construction: 1.390 ms, compared with 1.480 ms;
• cached predicate refinement: 291 ns versus 295 ns, within measurement noise;
• the internal directed raster shape path: 0.428 ms.

How was this patch tested?

• Full common module suite: 1,211 tests, 0 failures.
• Spark 4.1 BroadcastIndexJoinSuite: 66 tests, 0 failures, including raster RS_DWithin coverage.
• Flink Geography suites: 39 tests, 0 failures.
• Added WKT, WKB, serialization, polygon winding, shell/hole, repeated-vertex, near-hemisphere, raster-footprint, nested collection, and empty-polygon regression coverage.
• Spotless, Markdown lint, and commit hooks passed.

Did this PR include necessary documentation updates?

• Yes. Spark SQL and Flink documentation now describe simple-feature polygon ring roles and the at-most-one-hemisphere behavior for ST_Area, ST_Contains, ST_Intersects, and ST_Within.
• The existing predicate SVGs remain unchanged because they depict valid sub-hemisphere relationships and do not imply winding-sensitive behavior.