refactor: Move manifest manager lock to MitoRegion

[evenyag]

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Refer to a related PR or issue link (optional)

#3456

What's changed and what's your intention?

This PR is a part of #3456

It moves methods in RegionManifestManagerInner to RegionManifestManager. Now the MitoRegion uses a lock to protect the manager. We can use that lock to ensure there is only one task updating manifest and VersionControl.

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.

[codecov]

Codecov Report

Attention: Patch coverage is 92.03540% with 9 lines in your changes are missing coverage. Please review.

Project coverage is 85.26%. Comparing base (02f806f) to head (ecaa8ca).
Report is 2 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3689      +/-   ##
==========================================
- Coverage   85.57%   85.26%   -0.32%     
==========================================
  Files         957      962       +5     
  Lines      159226   160265    +1039     
==========================================
+ Hits       136258   136644     +386     
- Misses      22968    23621     +653     

[v0y4g3r]

LGTM

[killme2008]

LGTM