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Add Metrics for MergeTree Part Types

Add metrics for MergeTree parts (Wide/Compact/InMemory) types. #19381 (Azat Khuzhin).
Added metrics to monitor the number and types of MergeTree parts including Wide, Compact, and InMemory.

Why it matters

To provide users with detailed insights and visibility into the different types of parts within MergeTree tables, helping in performance monitoring, troubleshooting, and capacity planning.

How to use it

These metrics are automatically collected and exposed by ClickHouse; users can query the relevant system tables or integrate with monitoring tools to utilize the new part-type metrics without additional configuration.