feat: add num_rows and num_row_groups to manifest

[waynexia]

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What's changed and what's your intention?

Add num_rows and num_row_groups to mito manifest.

Checklist

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

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 84.79%. Comparing base (5bcd7a1) to head (9126c9c).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4183      +/-   ##
==========================================
- Coverage   85.10%   84.79%   -0.31%     
==========================================
  Files        1022     1022              
  Lines      179849   179906      +57     
==========================================
- Hits       153059   152555     -504     
- Misses      26790    27351     +561