Build on Apache Iceberg 1.3.1.
Support Apache Spark 3.1, 3.2, 3.3, and 3.4.
Add geometry aggregate functions (st_minx, st_maxx, st_miny, st_maxy) which can be pushdown to Iceberg's manifest file using Spark 3.4, see examples in the test file TestGeometryAggregatePushDown.java.