Made some preparations for Conway era

[Soupstraw]

Description

This PR makes some changes in preparation for the Conway era. The changes are based on IntersectMBO/formal-ledger-specifications#40.

Rule graph

   BBODY
    |
    |-------------------------------|
    v                               v
   TICK                            LEDGERS
    |                               |
    |---------|                     |
    v         v                     v
   RUPD     ~NEWEPOCH~            ~LEDGER~
              |                     |
              |----------|          |--------|-------------------|-----------|
              v          v                   v                   v           v
            ~EPOCH~     +ENACTMENT+         DELEGS              UTXOW       +TALLY+
              |                              |                   |
              |---------|------------|       v                   |
              v         v            v      DELPL                v
             SNAP      POOLREAP    -UPEC-    |                  UTXO
                                             |--------|          |
                                             v        v          v
                                            POOL     DELEG     ~UTXOS~

-..- Removed
+..+ Added
~..~ Modified

New typeclasses

This PR turns some data types into typeclasses. PPUPState and PPUPPredFailure are now closed type families parametrized by era. This makes it easy to swap out fields of those types in Conway and future eras. I also added a new type family TallyState which has a nullary constructor NoTallyState in all eras before Conway.

Changes to rules

The old PParam update logic got replaced with governance actions and with that I got rid of the UPEC rule and added TALLY and ENACTMENT rules. The TALLY rule has been implemented as specified in the formal specification. ENACTMENT is just a stub for now.

Conway transaction body

Since protocol parameters are no longer a part of TxBody, I added a getter for the PParamsUpdate in the transaction body that returns an empty update starting from conway. This got rid of some protocol version constraints and made it possible to reuse some functions from previous eras.

Ledger state

The ledger state datatype now has a tally state. In pre-Conway eras this field uses the datatype of ShelleyTallyState which only has a nullary constructor, but in the Conway era it is a map of governance action ID to governance action state, which stores information about the governance action and all the votes that the action has received.

This PR also adds an EraTallyState class that specifies the type instance of TallyState in that era and also provides a way to create an empty TallyState of that type.

resolves #3147
resolves #3148
resolves #3159

Checklist

• Commit sequence broadly makes sense
• Commits have useful messages
• New tests are added if needed and existing tests are updated
• Any changes are noted in the changelog
• Code is formatted with ormolu (which can be run with scripts/ormolise.sh
• Self-reviewed the diff

[lehins]

I haven't matched it to the spec, but I think @JaredCorduan already did that and I am sure we'll be going through the rules in the end again anyways. Implementation wise it looks great. Few minor remarks, like redundant constraints and such, but nothing terribly important.

There was a couple of prior comments that were marked as resolved, but in fact weren't resolved, so I unresolved them. I am sure it was an accident, but mentioning it just in case.

Massive work, great job @Soupstraw!

[JaredCorduan]

I haven't matched it to the spec, but I think @JaredCorduan already did that and I am sure we'll be going through the rules in the end again anyways.

yes to both!

Massive work, great job @Soupstraw!

💯 ☝️