Use Pretty for rendering errors instead of Show

[newhoggy]

Changelog

- description: |
    Use `Pretty` for rendering errors instead of `Show`
# 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

Pretty is a typeclass from the prettyprinter package.

It has support for powerful formatting options such as colour and layout.

By switching to Pretty we are able to use these features. Furthermore, plutus errors and types have Pretty instances so can utilise that to pretty print their error messages in an ergonomic way.

This package is also used by optparse-applicative which means it is already a dependency.

Pretty also doesn't suffer the problem with Show where many of the instances render strings that are not friendly to users.

Ledger also have Show instances that may not behave the way we want.

Our Pretty instances can help us break away from this status quo.

In order to minimise change, this PR does not utilise these features.

Instead, it preserves formatting of all errors exactly as before leaving future PRs to tidy up the formatting and layout of our rendered errors.

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]

I like the change, but I have a few remarks.