Remove ProtocolParameters

[smelc]

Changelog

- description: |
    Remove the ProtocolParameters type, that has been deprecated for a while
# 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

ProtocolParameters had been deprecated in favor the ledger's PParams type. We are now removing ProtocolParameters altogether.

Fixes #384

How to trust this PR

• It's deletion only
• Execute git grep ' ProtocolParameters ' in cardano-cli and observe that there are no hits
• ProtocolParameters has been removed from cardano-node in tx-generator: remove usage of cardano-api's ProtocolParameters (WIP) cardano-node#6090

Checklist

• Commit sequence broadly makes sense and commits have useful messages
• Self-reviewed the diff

[smelc]

This is blocked on merging IntersectMBO/cardano-node#6090 in cardano-node so this is going to stay in draft a little while. The performance team has been notified of 6090, but needs to act on stopping to support Byron to merge it.