feat(cdc): add cdc backfill grafana metrics

[StrikeW]

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What's changed and what's your intention?

As title.

close #13177

Checklist

• I have written necessary rustdoc comments
• I have added necessary unit tests and integration tests
• I have added test labels as necessary. See details.
• I have added fuzzing tests or opened an issue to track them. (Optional, recommended for new SQL features Sqlsmith: Sql feature generation #7934).
• My PR contains breaking changes. (If it deprecates some features, please create a tracking issue to remove them in the future).
• All checks passed in ./risedev check (or alias, ./risedev c)
• My PR changes performance-critical code. (Please run macro/micro-benchmarks and show the results.)

• My PR contains critical fixes that are necessary to be merged into the latest release. (Please check out the details)

Documentation

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Release note

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (a73d940) 68.19% compared to head (3ea305f) 68.19%.

Additional details and impacted files

@@           Coverage Diff           @@
##             main   #13777   +/-   ##
=======================================
  Coverage   68.19%   68.19%           
=======================================
  Files        1524     1524           
  Lines      262232   262250   +18     
=======================================
+ Hits       178829   178847   +18     
  Misses      83403    83403           

Flag	Coverage Δ
rust	68.19% <100.00%> (+<0.01%)	⬆️

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