Add icebergHash and icebergBucket

Why it matters

This feature introduces native support for Iceberg's bucket transform partitioning by implementing the required hash and bucket functions. It solves the problem of efficient data pruning and query optimization on Iceberg tables with bucket partitions, improving performance and reducing query latency.

How to use it

Users can utilize the new icebergHash and icebergBucket functions when working with Iceberg tables that are partitioned by the bucket transform. This allows ClickHouse to perform data file pruning properly on such tables to speed up query execution.