Support for Empty Tuples in ClickHouse

Why it matters

This feature introduces the ability to handle empty tuples, which can be used to represent or process data structures where no elements are present. It enhances ClickHouse's flexibility in handling complex data types and edge cases involving tuples without any fields.

How to use it

Users can now utilize empty tuples directly in their queries or table schemas where tuple types are allowed. No special configuration is needed; just define or use tuples with zero elements as needed.