feat: add max-metadata check for credit class and credit batch

[aleem1314]

Description

Closes: #520

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Author Checklist

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Reviewers Checklist

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• confirmed the correct type prefix in the PR title
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• reviewed state machine logic
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[codecov]

Codecov Report

Merging #540 (8554f3a) into master (cbc060a) will decrease coverage by 0.00%.
The diff coverage is 100.00%.

❗ Current head 8554f3a differs from pull request most recent head d0bcc11. Consider uploading reports for the commit d0bcc11 to get more accurate results

@@            Coverage Diff             @@
##           master     #540      +/-   ##
==========================================
- Coverage   77.45%   77.44%   -0.01%     
==========================================
  Files         100      100              
  Lines       12760    12765       +5     
==========================================
+ Hits         9883     9886       +3     
- Misses       2287     2288       +1     
- Partials      590      591       +1     

Flag	Coverage Δ
experimental-codecov	77.44% <100.00%> (-0.01%)	⬇️
stable-codecov	68.22% <100.00%> (-0.01%)	⬇️

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[technicallyty]

lgtm

[ryanchristo]

tACK