chore: add more metrics to hub stream reader

[aditiharini]

We need some more instrumentation to understand how much of a time to read delay is accounted for by the hub stream -> redis step vs the redis -> postgres step.

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PR-Codex overview

This PR adds more metrics to HubSubscriber.

Detailed summary

• Added shardKey property to EventStreamHubSubscriber
• Added metrics for batch size and process time per event and per batch

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[changeset-bot]

🦋 Changeset detected

Latest commit: af649f3

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@farcaster/shuttle	Patch

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Name	Status	Preview	Comments	Updated (UTC)
hub-monorepo	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Sep 10, 2024 10:04pm

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 7 lines in your changes missing coverage. Please review.

Project coverage is 44.32%. Comparing base (1880070) to head (af649f3).
Report is 343 commits behind head on main.

Files with missing lines	Patch %	Lines
packages/shuttle/src/shuttle/hubSubscriber.ts	0.00%	7 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##             main    #2302       +/-   ##
===========================================
- Coverage   74.05%   44.32%   -29.74%     
===========================================
  Files          99      146       +47     
  Lines        9425    25496    +16071     
  Branches     2097     9113     +7016     
===========================================
+ Hits         6980    11300     +4320     
- Misses       2327    12437    +10110     
- Partials      118     1759     +1641     

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[sanjayprabhu]

Please add a changeset