feat(x/ecocredit): require metadata for create batch

[ryanchristo]

Description

Ref: #1623 (comment)

Credit batch metadata cannot be updated if the batch is sealed. This pull request ensures credit batch metadata is included when creating a new credit batch (class and project metadata is still optional - they can be updated).

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Author Checklist

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I have...

• included the correct type prefix in the PR title
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• included the necessary unit and integration tests
• added a changelog entry to CHANGELOG.md
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Reviewers Checklist

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I have...

• confirmed the correct type prefix in the PR title
• confirmed ! in the type prefix if API or client breaking change
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• reviewed state machine logic
• reviewed API design and naming
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• reviewed tests and test coverage
• manually tested (if applicable)

[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (main@e4fb4af). Click here to learn what that means.
The diff coverage is 100.00%.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1630   +/-   ##
=======================================
  Coverage        ?   77.62%           
=======================================
  Files           ?      266           
  Lines           ?    19484           
  Branches        ?        0           
=======================================
  Hits            ?    15125           
  Misses          ?     3490           
  Partials        ?      869           

Impacted Files	Coverage Δ
x/ecocredit/base/types/v1/msg_create_batch.go	95.12% <100.00%> (ø)