DRAFT: add packet handler spec

[AdityaSripal]

Description

closes: #XXXX

---

Before we can merge this PR, please make sure that all the following items have been
checked off. If any of the checklist items are not applicable, please leave them but
write a little note why.

• Linked to GitHub issue with discussion and accepted design, OR link to spec that describes this work.
• Wrote unit and integration tests.
• Added relevant natspec and godoc comments.
• Provide a conventional commit message to follow the repository standards.
• Re-reviewed Files changed in the GitHub PR explorer.
• Review SonarCloud Report in the comment section below once CI passes.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 99.84%. Comparing base (0a9e240) to head (adc2a2a).
Report is 36 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #294      +/-   ##
==========================================
+ Coverage   98.69%   99.84%   +1.15%     
==========================================
  Files          11       14       +3     
  Lines         535      643     +108     
==========================================
+ Hits          528      642     +114     
+ Misses          7        1       -6     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.