add support for script based drep on update certificate

[CarlosLopezDeLara]

Changelog

- description: |
    add support for script based drep on update certificate: --drep-script-hash HASH
# 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
  # - refactoring    # QoL changes
  # - 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

Resolves #880

How to trust this PR

Now we have the ability to supply a script hash

cardano-cli conway governance drep update-certificate \
--drep-script-hash 8f33600845940d65bdbc7ea7a247a7997aa8558649128fa82c4c0468 \
--drep-metadata-url https://raw.githubusercontent.com/cardano-foundation/CIPs/master/CIP-0119/examples/drep.jsonld \
--drep-metadata-hash fecc1773db89b45557d82e07719c275f6877a6cadfd2469f4dc5a7df5b38b4a4 \
--out-file drep-update.cert

It produces the certificate:

{
    "type": "CertificateConway",
    "description": "DRep Update Certificate",
    "cborHex": "83128201581c8f33600845940d65bdbc7ea7a247a7997aa8558649128fa82c4c046882785e68747470733a2f2f7261772e67697468756275736572636f6e74656e742e636f6d2f63617264616e6f2d666f756e646174696f6e2f434950732f6d61737465722f4349502d303131392f6578616d706c65732f647265702e6a736f6e6c645820fecc1773db89b45557d82e07719c275f6877a6cadfd2469f4dc5a7df5b38b4a4"
}

And if we pass the cborHex over the diagnostics mode on cbor.me we see it complies with the cddl

update_drep_cert = (18, drep_credential, anchor / nil)
drep_credential = credential
credential = [0, addr_keyhash // 1, scripthash]

[18, [1, h'8F33600845940D65BDBC7EA7A247A7997AA8558649128FA82C4C0468'], ["https://raw.githubusercontent.com/cardano-foundation/CIPs/master/CIP-0119/examples/drep.jsonld", h'FECC1773DB89B45557D82E07719C275F6877A6CADFD2469F4DC5A7DF5B38B4A4']]

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

[Jimbo4350]

@CarlosLopezDeLara adding the new option on the command line to the PR description is useful because this then automatically ends up in the changelog