Switch ShelleyGenesis parameterization on era in favor of crypto

[lehins]

Description

This PR:

• Switch ShelleyGenesis era -> ShelleyGenesis c, which means that PParams in the type are restricted to PParams (ShelleyEra c), instead of ShelleyParams era. This is necessary, because we do in fact want the pparams from the Shelley era, instead of any other era that uses the same type.
• Removes TranslateEra instance for Shelleygenesis, since it makes no sense to upgrade a type that is not parameterized by an era. It was wrong to add that instance to begin with.
• Improves CanStartFromGenesis class, by abstracting the PParam abstract logic with fromShelleyPParams, which is the only part that is different between eras.
• Fixes ConwayGenesis, by adding AlonzoGenesis, which is needed for the ability to upgrade PParams all the way from ShelleyEra.
• Removed Cardano.Ledger.Babbage.Genesis module, since now it is completely empty, because duplicated logic for upgrading PParams was removed.

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

[JaredCorduan]

this looks really nice! let's just check with @bartfrenk before we merge it, to make sure we are not working against their plans to separate the genesis data from the can start data.

[Soupstraw]

Looks good