Adds support for setting the Iceberg catalog name, and for using the catalog type property.
NOTE: This release makes a backward-incompatible change to setting catalog properties. The iceberg.catalog property is now for setting the catalog name, and it is optional. If not set it defaults to iceberg. The catalog implementation is set either via iceberg.catalog.type or iceberg.catalog.catalog-impl, which is more consistent with Iceberg configuration in other platforms.