Clean hardfork switches

[teodanciu]

Closes: #3104

Answers the question: which HardFork switches can we remove from the code without affecting the state

How I checked:

1. Checked out cardano-node (tag 1.35.3) and synced up with mainnet until slot 76138419 (the tip at the time)
2. Checked out db-analyser (part of ouroboros-network), at branch release/cardano-node-1.35.x
3. Took snapshots of the ledger state, using db-analyser, corresponding to the first slots of each era
4. For each tested switch:
   • set the switch to True in cardano-ledger in a branch off tag node/1.35.3
   • run db-analyzer pointing to the aforementioned cardano-ledger branch:
     • analyzing from a slot that is not affected by the switch (earlier than the protocol version from the condition)
     • taking a snapshot of the ledger state for slots corresponding to the snapshots taken at step 2
   • this db-analyzer had two possible outcomes: an error or a snapshot. The error is an indication that the switch cannot be removed. In case there was no error, the sha256 sum of the produced snapshot was compared with that of the corresponding snapshot produced at step 2 (using the code with the HardFork switch intact)

1. allowMIRTransfer pp = pvMajor (getField @"_protocolVersion" pp) > 4 ❎

Ran:

cabal run ouroboros-consensus-cardano-tools:db-analyser2 -- --db /home/teodora/cardano-mainnet/db/db-mainnet --only-immutable-db --analyse-from 23068800 --store-ledger 39916975  cardano --config /home/teodora/cardano-mainnet/config.json

because 23068800 is the first slot in Mary (version 4) and 39916975 is the first slot in the next era

This resulted in an error: ExtValidationErrorLedger (HardForkLedgerErrorFromEra S (S (S (Z (WrapLedgerErr {unwrapLedgerErr = BBodyError (BlockTransitionError [LedgersFailure (LedgerFailure (DelegsFailure (WithdrawalsNotInRewardsDELEGS (fromList [(RewardAcnt {getRwdNetwork = Mainnet, getRwdCred = KeyHashObj (KeyHash "7f5287ac749c44f8b517165a35ea60a0a165904b25da29749d2366e4")},Coin 220383)]))))])})))))

So I concluded it can't be removed.

---

2. aggregatedRewards pp = pvMajor (getField @"_protocolVersion" pp) > 2 ❎

set to True, trying to take a snapshot from 4492800 (first Shelley slot(v2)) to 16588800 (first Allegra slot (v3)) resulted in:
ExtValidationErrorLedger (HardForkLedgerErrorFromEra S (Z (WrapLedgerErr {unwrapLedgerErr = BBodyError (BlockTransitionError [LedgersFailure (LedgerFailure (DelegsFailure (WithdrawalsNotInRewardsDELEGS (fromList [(RewardAcnt {getRwdNetwork = Mainnet, getRwdCred = KeyHashObj (KeyHash "24f1b3791037e55363815fc4b788b886cd1d82a2f2d39e17196cd1a4")},Coin 431236474)]))))])})))

---

3. validatePoolRewardAccountNetID pp = pvMajor (getField @"_protocolVersion" pp) > 4 ❎

set to True, trying to take a snapshot from 23068800 (first Mary slot(v2)) to 39916975 (first Alonzo slot (v3)) resulted in: ExtValidationErrorLedger (HardForkLedgerErrorFromEra S (S (S (Z (WrapLedgerErr {unwrapLedgerErr = BBodyError (BlockTransitionError [LedgersFailure (LedgerFailure (DelegsFailure (DelplFailure (PoolFailure (WrongNetworkPOOL Mainnet Testnet (KeyHash "ae8ee8f5676a3c3aadefd0ee7adb57ebbd39dd7126c8517e718dc4c1"))))))])})))))

---

4. forgoRewardPrefilter pp = pvMajor (getField @"_protocolVersion" pp) > 6 ❎

set to True, trying to take a snapshot from 43372972 (v6) to 76138419 resulted in: ExtValidationErrorLedger (HardForkLedgerErrorFromEra S (S (S (S (Z (WrapLedgerErr {unwrapLedgerErr = BBodyError (BlockTransitionError [ShelleyInAlonzoPredFail (LedgersFailure (LedgerFailure (DelegsFailure (DelplFailure (DelegFailure (StakeKeyNonZeroAccountBalanceDELEG (Just (Coin 658031))))))))])}))))))

---

5. translateTimeForPlutusScripts pp = pvMajor (getField @"_protocolVersion" pp) > 5 ✔️

set to True, a snapshot of 76138419 (latest slot that I had synced with mainnet) was generated with the same sha256 of the snapshot taken with the switch enabled (9aafb9e44500f84d2a59dfd8019934dd42a947edf976c35d90fa6bb4136604dd )

---

6. allowScriptStakeCredsToEarnRewards pp = pvMajor (getField @"_protocolVersion" pp) > 4 ✔️

set to True, a snapshot of 76138419 with the original sha256 is generated

---

7. allowOutsideForecastTTL pp =let mv = pvMajor (getField @"_protocolVersion" pp) in mv == 5 || mv == 6 ✔️

set to True, a snapshot of 76138419 with the original sha256 is generated

---

8. missingScriptsSymmetricDifference ❔

I forgot why we can't switch this off even if the state is the same

[JaredCorduan]

looks great, thank you @teodanciu , wonderful clean up! (my only comment is about the orig file).

[lehins]

This is a great cleanup!!! Thank you.
Just one minor comment