Support use-preferred-write-partitioning for the Iceberg connector

[epogash]

When trying to utilize use-preferred-write-partitioning for Iceberg, there is no effect.

[findepi]

#9834 adds repartitioning support for Iceberg.

per

trino/core/trino-main/src/main/java/io/trino/sql/planner/LogicalPlanner.java

Lines 542 to 553 in 36ff8b5

	Optional<PartitioningHandle> partitioningHandle = writeTableLayout.get().getPartitioning();
	if (partitioningHandle.isPresent()) {
	partitioningScheme = Optional.of(new PartitioningScheme(
	Partitioning.create(partitioningHandle.get(), partitionFunctionArguments),
	outputLayout));
	}
	else {
	// empty connector partitioning handle means evenly partitioning on partitioning columns
	preferredPartitioningScheme = Optional.of(new PartitioningScheme(
	Partitioning.create(FIXED_HASH_DISTRIBUTION, partitionFunctionArguments),
	outputLayout));
	}

to fully leverage cost-based write partitioning selection, for identity-based partitions, we need not to return partitioning handle, and set only ConnectorNewTableLayout#partitionColumns