Fix issues that prevent basic sumbitTx from passing conformance

[Soupstraw]

Description

This PR fixes some issues that prevent the conformance tests on most of the ImpTests from passing.

The VKey type is now translated to a pair of the VKey and the hash of that VKey, similar to how Timelocks are translated.

ConwayRegCert now translates to the Reg certificate, which is a newly added certificate in the spec. The previous approach of translating that cert to Deleg did not work, because the Deleg cert always requires witnessing, while the legacy registration cert does not.

related: IntersectMBO/formal-ledger-specifications#616

Checklist

• Commit sequence broadly makes sense and commits have useful messages
• New tests are added if needed and existing tests are updated
• All visible changes are prepended to the latest section of a CHANGELOG.md for the affected packages.
  New section is never added with the code changes. (See RELEASING.md)
• When applicable, versions are updated in .cabal and CHANGELOG.md files according to the
  versioning process.
• The version bounds in .cabal files for all affected packages are updated.
  If you change the bounds in a cabal file, that package itself must have a version increase. (See RELEASING.md)
• Code is formatted with fourmolu (use scripts/fourmolize.sh)
• Cabal files are formatted (use scripts/cabal-format.sh)
• hie.yaml has been updated (use scripts/gen-hie.sh)
• Self-reviewed the diff

[aniketd]

Nice work figuring out all the really difficult bits! 🙌

[aniketd]

Awesome! 🙌

[teodanciu]

Looks good to me