Add metrics for baseline resync

[yuwmao]

Add statistic information to the pg meta/shard meta message.
Add metrics to track the progress.

• DonerSnapshotMetrics is in memory;
• ReceiverSnapshotMetrics persists the progress.

Currently, use DefaultBucket for histogram metrics. We can refine it after the BR performance test.

[codecov-commenter]

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Codecov Report

Attention: Patch coverage is 57.27273% with 47 lines in your changes missing coverage. Please review.

Project coverage is 61.12%. Comparing base (1746bcc) to head (86519f6).
Report is 46 commits behind head on main.

Files with missing lines	Patch %	Lines
src/lib/homestore_backend/hs_homeobject.hpp	54.16%	22 Missing ⚠️
...lib/homestore_backend/snapshot_receive_handler.cpp	62.22%	16 Missing and 1 partial ⚠️
...ib/homestore_backend/replication_state_machine.cpp	0.00%	4 Missing ⚠️
src/lib/homestore_backend/hs_pg_manager.cpp	0.00%	2 Missing ⚠️
src/lib/homestore_backend/pg_blob_iterator.cpp	81.81%	1 Missing and 1 partial ⚠️

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Additional details and impacted files

@@            Coverage Diff             @@
##             main     #266      +/-   ##
==========================================
- Coverage   63.15%   61.12%   -2.04%     
==========================================
  Files          32       33       +1     
  Lines        1900     2822     +922     
  Branches      204      332     +128     
==========================================
+ Hits         1200     1725     +525     
- Misses        600      921     +321     
- Partials      100      176      +76     

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[xiaoxichen]

a few suggestion for metrics.

Q: What is the reason to introduce metrics in testing code ?

[yuwmao]

a few suggestion for metrics.

Q: What is the reason to introduce metrics in testing code ?

It is convenient for us to troubleshoot the http/metrics problems in the local dev environment if needed(disabled by default).