Add Generic Implementation for Named Collections in ClickHouse

Why it matters

This feature allows users to define and manage named collections with arbitrary structured data, simplifying configuration and reuse of complex settings or parameters. It enhances organization and accessibility by providing a dedicated access type and system table to inspect the named collections.

How to use it

Users can create and manage named collections using the new generic structure, specify access via the provided access type, and query existing named collections through the system.named_collections system table.