key non-extended-key: support drep extended keys

[smelc]

Changelog

- description: |
    Support converting a drep extended key to its non-extended version
# uncomment types applicable to the change:
  type:
  - feature        # introduces a new feature
  # - breaking       # the API has changed in a breaking way
  - compatible     # the API has changed but is non-breaking
  # - optimisation   # measurable performance improvements
  # - improvement    # QoL changes e.g. refactoring
  # - bugfix         # fixes a defect
  # - test           # fixes/modifies tests
  # - maintenance    # not directly related to the code
  # - release        # related to a new release preparation
  # - documentation  # change in code docs, haddocks...

Context

Fixes #358

Roadmap

• Add a golden test
• Merge Support DRep extended keys cardano-api#320
• Release cardano-api
• Merge Upgrade to cardano-api-8.26.0.0 #389
• Realize Support DRep extended keys cardano-api#320 misses something 🙃, so onto a new round of cardano-api PR/release/update cardano-cli
• Merge DRep extended key: add CastVerificationKeyRole cardano-api#327
• Release cardano-api, and update cardano-cli to use new cardano-api
• Merge this PR

Checklist

• Commit sequence broadly makes sense and commits have useful messages
• The change log section in the PR description has been filled in
• New tests are added if needed and existing tests are updated. These may include:
  • golden tests
  • property tests
  • round trip tests
  • integration tests
    See Running tests for more details
• NA The version bounds in .cabal files are updated
• CI passes. See note on CI. The following CI checks are required:
  • Code is linted with hlint. See .github/workflows/check-hlint.yml to get the hlint version
  • Code is formatted with stylish-haskell. See .github/workflows/stylish-haskell.yml to get the stylish-haskell version
  • Code builds on Linux, MacOS and Windows for ghc-8.10.7 and ghc-9.2.7
• Self-reviewed the diff

[carbolymer]

Should we have a description for that key here?

[smelc]

@carbolymer> I added a description in commit drep verification key: extended->non extended: specify description. Is that what you had in mind?

I did the minimal change to avoid disturbing existing tests and code.

[carbolymer]

Sorry, I should've been more explicit. It's an open question from my side whether we should have a description here.
@CarlosLopezDeLara what do you think, should we put a description here, and which one?

[CarlosLopezDeLara]

"Delegate Representative Verification Key"
@carbolymer

[carbolymer]

@smelc The text value is already defined here: https://github.com/input-output-hk/cardano-cli/blob/main/cardano-cli/src/Cardano/CLI/EraBased/Run/Governance.hs#L98
it would be nice to re-use it (and move it somewhere probably).

[smelc]

I made the constant a top-level symbol of Cardano.CLI.EraBased.Run.Key and reused it from Governance. I looked around but saw no obvious destinations and didn't want to introduce a Constant module.

@carbolymer> let me know if that suits you.

I also propose to put descriptions when converting other types of extended keys, but will do that in another PR, to avoid delaying this one.