chore: add more metrics about parquet and cache

[MichaelScofield]

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What's changed and what's your intention?

as title

useful for diagnosing slow queries

Checklist

• [ ] I have written the necessary rustdoc comments.
• [ ] I have added the necessary unit tests and integration tests.
• [ ] This PR requires documentation updates.

Summary by CodeRabbit

• New Features

  • Introduced a cache eviction metric for improved monitoring of cache performance.
  • Added a histogram metric to measure the time taken for loading Parquet metadata.

• Improvements

  • Enhanced observability of cache eviction reasons for better diagnostics.
  • Implemented performance tracking in the MetadataLoader for metadata loading efficiency.