feat: storage v2 serializer for sync

[shaoting-huang]

related: #39173

[sre-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: shaoting-huang
To complete the pull request process, please assign congqixia after the PR has been reviewed.
You can assign the PR to them by writing /assign @congqixia in a comment when ready.

The full list of commands accepted by this bot can be found here.

Needs approval from an approver in each of these files:

• OWNERS

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[codecov]

Codecov Report

Attention: Patch coverage is 63.07692% with 24 lines in your changes missing coverage. Please review.

Project coverage is 80.11%. Comparing base (5669016) to head (dcba33f).
Report is 3 commits behind head on master.

Files with missing lines	Patch %	Lines
...ernal/flushcommon/syncmgr/storage_v2_serializer.go	63.07%	21 Missing and 3 partials ⚠️

❌ Your patch check has failed because the patch coverage (63.07%) is below the target coverage (80.00%). You can increase the patch coverage or adjust the target coverage.

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #39663      +/-   ##
==========================================
+ Coverage   80.07%   80.11%   +0.03%     
==========================================
  Files        1464     1466       +2     
  Lines      203311   203494     +183     
==========================================
+ Hits       162809   163025     +216     
+ Misses      34676    34662      -14     
+ Partials     5826     5807      -19     

Components	Coverage Δ
Client	79.45% <ø> (ø)
Core	69.39% <ø> (ø)
Go	81.84% <63.07%> (+0.03%)	⬆️

Files with missing lines	Coverage Δ
...ernal/flushcommon/syncmgr/storage_v2_serializer.go	63.07% <63.07%> (ø)

... and 51 files with indirect coverage changes