refactor(x/ecocredit): update project id and batch denom

[ryanchristo]

Description

Closes: #1032

Update project id to include class id and batch denom to use project id rather than class id. This pull request also removes support for custom project ids but I can revert if we feel this is something we still want to support.

This pull request does not include the following items brought up in #1032 that are still being discussed in #883 and #1066:

• a reference id without unique constraints for convenient lookups
• global project ids rather than project ids scoped to credit classes
• support for multiple credit classes using a join table that would store a class-project-id

---

Author Checklist

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I have...

• included the correct type prefix in the PR title
• added ! to the type prefix if API or client breaking change
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• provided a link to the relevant issue or specification
• followed the guidelines for building modules
• included the necessary unit and integration tests
• added a changelog entry to CHANGELOG.md
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• updated the relevant documentation or specification
• reviewed "Files changed" and left comments if necessary
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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
• confirmed all author checklist items have been addressed
• reviewed state machine logic
• reviewed API design and naming
• reviewed documentation is accurate
• reviewed tests and test coverage
• manually tested (if applicable)

[codecov]

Codecov Report

Merging #1046 (39a603a) into master (b237a50) will decrease coverage by 6.04%.
The diff coverage is 58.82%.

@@            Coverage Diff             @@
##           master    #1046      +/-   ##
==========================================
- Coverage   68.97%   62.93%   -6.05%     
==========================================
  Files         216      213       -3     
  Lines       21312    19385    -1927     
==========================================
- Hits        14701    12200    -2501     
- Misses       5259     5908     +649     
+ Partials     1352     1277      -75     

Flag	Coverage Δ
experimental-codecov	?
stable-codecov	62.93% <58.82%> (-0.01%)	⬇️

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[technicallyty]

looks good - just one nit. i'm not partial to whether or not we do project ID's so ill approve once theres product consensus 👍🏻

[clevinson]

Concept ACK on removing custom project_id's and changing the batch denom as described here.

[technicallyty]

lgtm, pre-approving

[ryanchristo]

@aleem1314 can you review when you get a chance? 🙏

[aleem1314]

Pre approving