feat: Correct server metrics and add more metrics for scan

[evenyag]

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What's changed and what's your intention?

This PR improves existing metrics and adds more metrics for scan

• Adds an attach_timer() method and an OnDone stream adapter to observe the duration to fetch a stream, this fixes
  • GRPC_HANDLE_PROMQL_ELAPSED
  • GRPC_HANDLE_SQL_ELAPSED
  • EXEC_PLAN_ELAPSED
• Removes the METRIC_ prefix from metrics in query mod
• Move track_metrics to metrics mod and rename it
• Removes some metrics under servers mod as we already collect it in the HTTP middleware
• Combine query metrics into a histogram vec
• Register the gRPC metrics middleware
• Add more metrics to track scan cost

Checklist

• I have written the necessary rustdoc comments.
• I have added the necessary unit tests and integration tests.
• This PR does not require documentation updates.

[fengjiachun]

LGTM