Switch to use UnitIO in golden tests

[newhoggy]

Changelog

- description: |
    Switch to use `UnitIO` in golden tests.
# 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

UnitIO makes it clear that the test is a unit test and not a property test so there can be no confusion what kind of test it is.

The monad also adds type safety by not allow generators to be accidentally used as these should be reserved for property tests.

The setup for UnitIO tests is also slightly easier.

How to trust this PR

Highlight important bits of the PR that will make the review faster. If there are commands the reviewer can run to observe the new behavior, describe them.

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

[carbolymer]

Why watchdog is removed?

[newhoggy]

I'm interesting in seeing if it is need in CI by allowing it to run there for a few runs.

If it still happens, we can integrate the watchdog into UnitIO and not need to change the cardano-cli code.

[Jimbo4350]

Add an an explanation as to why we are using UnitIO in the description.

[newhoggy]

More information has been added to the Context section.

Comments addressed