HIVE-26319: Iceberg integration: Perform update split early

[kasakrisz]

What changes were proposed in this pull request?

Rewrite update statements of iceberg tables to multi insert statement similarly in case of native acid tables.

When generating the rewritten statement:

• Get the virtual columns from the table's storage handler in case of non native acid tables
• Include the old values to the select clause of the delete branch of the multi insert statement.

When executing the multi insert:

• Two iceberg writers are used which produce a data delta file and a delete delta file. The result of these writers should be merged into one FilesForCommit if both writers are run in the same task.
• In case of more complex statements (ex. partitioned and/or bucketed) more than one Tez task produces commit info so this patch enables storing all of them.
• Every FileSinkOperator creates its own jobConf instance because the iceberg write operation is stored in it and it is different in both instance.

Why are the changes needed?

See #2855

• Preparation for iceberg Merge implementation.

Does this PR introduce any user-facing change?

No.

How was this patch tested?

mvn test -Dtest.output.overwrite -Dtest=TestIcebergLlapLocalCliDriver -Dqfile=update_iceberg_partitioned_orc.q -pl itests/qtest-iceberg -Piceberg -Pitests
mvn test "-Dtest=TestHiveIcebergV2#testUpdateStatementWithPartitionAndSchemaEvolution[*AVRO*tez*HIVE_CATALOG*false]" -pl iceberg/iceberg-handler -Drat.skip -Piceberg
mvn test -Dtest=TestHiveIcebergInserts#testInsertOverwriteNonPartitionedTable[*ORC*tez*HIVE_CATALOG*false] -pl iceberg/iceberg-handler -Piceberg -Drat.skip