Add Basic Metrics for Kafka Table Monitoring

Why it matters

Provides visibility into the status and performance of Kafka engine tables by exposing essential monitoring metrics. This helps users to better track Kafka ingestion, diagnose issues, and optimize data processing.

How to use it

The metrics are automatically available once you use the engine=Kafka engine for a table. You can monitor these metrics via the existing ClickHouse metrics interfaces or integrate them with your monitoring system.