[GH-2830] Adds Geography dual-dispatch to ST_GeometryType

[zhangfengcdt]

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 #<issue_number>

What changes were proposed in this PR?

• Adds Geography dual-dispatch to ST_GeometryType — returns type strings like ST_Point, ST_Polygon for both Geometry and Geography inputs.
• Follow-up to [GH-2830] Improve Geography query support - core #2831; L1 tier (Geography path delegates to JTS via "ST_" + getJTSGeometry().getGeometryType()).

How was this patch tested?

• mvn -pl common -am test -Dtest=FunctionTest
• New Spark SQL cases in GeographyFunctionTest

Did this PR include necessary documentation updates?

• Yes, I have updated the documentation.

[Copilot]

Pull request overview

This PR adds Geography support to the existing ST_GeometryType Spark SQL expression via dual-dispatch, returning ST_<JTSGeometryType> strings consistently for both Geometry and Geography inputs.

Changes:

• Add Geography implementation for geometryType in common ("ST_" + toJTS(g).getGeometryType()).
• Update Spark SQL ST_GeometryType expression to dispatch to Geometry or Geography functions based on input type.
• Add unit/integration tests plus new Geography SQL docs entry for ST_GeometryType.

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
spark/common/src/main/scala/org/apache/spark/sql/sedona_sql/expressions/Functions.scala	Enable dual-dispatch for ST_GeometryType to support Geography inputs.
common/src/main/java/org/apache/sedona/common/geography/Functions.java	Add Geography geometryType implementation delegating through JTS.
common/src/test/java/org/apache/sedona/common/Geography/FunctionTest.java	Add Geography unit tests for geometryType (including null handling).
spark/common/src/test/scala/org/apache/sedona/sql/geography/GeographyFunctionTest.scala	Add Spark SQL integration tests for Geography ST_GeometryType.
docs/api/sql/geography/Geography-Functions.md / docs/api/sql/geography/Geography-Functions/ST_GeometryType.md	Document Geography ST_GeometryType and add it to the function index.

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