Added a Notion of Obsolete Settings

Why it matters

This feature helps maintain backward compatibility by recognizing obsolete settings without impacting system behavior. It prevents errors or warnings when users attempt to use settings that are no longer effective, thereby smoothing upgrades and transitions.

How to use it

Users can continue to include obsolete settings like allow_experimental_low_cardinality_type in their configuration or queries, but these settings will be ignored by ClickHouse without causing errors or affecting functionality.