Fix missing script proposals in transaction building

[carbolymer]

Changelog

- description: |
    `TxInsReference` is no longer parameterised by `build`.
    New functions `mkFeatured`, `setTxProposalProcedures`, `setTxVotingProcedures`, `mkTxVotingProcedures`, `mkTxProposalProcedures`, `convProposalProcedures`, and `buildTxWithToMaybe`.
    New generator `genValidTxBody`.
    Fix missing script proposals in transaction building [#594](https://github.com/IntersectMBO/cardano-api/issues/594).
# 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

Fixes #594

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]

LGTM!

[Jimbo4350]

Revert all the changes wrt to data types. I don't want to break the api twice because there may be a way to remove BuildTxWith. Just fix the bug we have encountered.

[Jimbo4350]

LGTM, some instances can be removed and some minor refactors.

[Jimbo4350]

Why? We also want to generate Nothing even when the feature is available in a given era.

[carbolymer]

Previous implementation was always generating Nothing, because the first argument of <|> was never empty.