key non-extended-key: support CC keys

[smelc]

Note

Needs IntersectMBO/cardano-api#514 merged and released and API update to be merged

Changelog

- description: |
    key non-extended-key: support CC keys
# 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 #705

Checklist

• Commit sequence broadly makes sense and commits have useful messages
• New tests are added if needed and existing tests are updated. See Running tests for more details
• Self-reviewed the diff

[smelc]

cc @disassembler

[smelc]

Being integrated in #720, so will probably be closed soon.

[smelc]

Got superseded by #720 in the end