CDDL with typeclasses: conway

[aniketd]

Description

New library named cddl for Conway to implement typeclass-based cuddle definitions to generate .cddl files from.

Follow-up PRs should implement for Dijkstra.

This is the second phase in our efforts to address #5194

NOTE

codegen on CI is expected to FAIL, and its diff is important to know exactly what has changed in the new implementation.

• Merge CDDL with typeclasses: mary, alonzo, babbage #5443 first

Checklist

• Commits in meaningful sequence and with useful messages.
• Tests added or updated when needed.
• CHANGELOG.md files updated for packages with externally visible changes.
  NOTE: New section is never added with the code changes. (See RELEASING.md).
• Versions updated in .cabal and CHANGELOG.md files when necessary, according to the
  versioning process.
• Version bounds in .cabal files updated when necessary.
  NOTE: If bounds change in a cabal file, that package itself must have a version increase. (See RELEASING.md).
• Code formatted (use scripts/fourmolize.sh).
• Cabal files formatted (use scripts/cabal-format.sh).
• CDDL files are up to date (use scripts/gen-cddl.sh)
• hie.yaml updated (use scripts/gen-hie.sh).
• Self-reviewed the diff.

[lehins]

This looks awesome!!!
Please remove changes to actual CDDL files, since it results in CI failure and breaks master: https://github.com/IntersectMBO/cardano-ledger/actions/runs/19923202590/job/57119367102?pr=5456

We had to undo changes that were introduced in previous PRs: #5445 and #5462

Don't get me wrong, I am glad you did include these changes to generated files in this PR for the purpose of review, since it gives more confidence that changes to huddle spec do not affect the correctness of CDDL generation. But, we should revert them and only apply them once we are ready to switch to this class based approach on permanent basis.