fix: Small optimizations for merge code

[adityapk00]

1. Don't create dup Buffer objects
2. Don't recompute tsHash

Motivation

Small optimizations after profiling

Merge Checklist

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• PR title adheres to the conventional commits standard
• PR has a changeset
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PR-Codex overview

This PR focuses on small optimizations for the merge code.

Detailed summary

• Added cloneMessage function in messageDataBytes.test.ts
• Imported makeTsHash function in store.test.ts
• Optimized code in onChainEvent.ts and store.ts

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[changeset-bot]

🦋 Changeset detected

Latest commit: aa1ee33

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

This PR includes changesets to release 1 package

Name	Type
@farcaster/hubble	Patch

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Name	Status	Preview	Comments	Updated (UTC)
hub-monorepo	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Feb 12, 2024 3:21pm

[codecov]

Codecov Report

Attention: 3 lines in your changes are missing coverage. Please review.

Comparison is base (330ce83) 73.98% compared to head (aa1ee33) 74.09%.

Files	Patch %	Lines
apps/hubble/src/storage/stores/store.ts	83.33%	3 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1694      +/-   ##
==========================================
+ Coverage   73.98%   74.09%   +0.11%     
==========================================
  Files          99       99              
  Lines        9263     9257       -6     
  Branches     2082     2079       -3     
==========================================
+ Hits         6853     6859       +6     
+ Misses       2289     2277      -12     
  Partials      121      121              

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