Sync executable with formal spec - NEWPP STS

[uroboros]

• in the formal spec in FIG 50 (Eqs 25, 26), in the formula for oblg_new, the spec uses in effect firstSlot, while in the exec spec we use slotFromEpoch e.

[mgudemann]

I think we return the clearPup utxoSt ?

[uroboros]

I think we return the clearPup utxoSt ?

you're right (I see now was reviewing a slightly stale NewPP)