Encode Value in Compact form in UTxO

[lehins]

It is counterproductive to uncompact the value in order to store it on disk in the ledger state. There is not really requirement for TxOut to be serialized in the same format in the ledger as it is in the transaction. It is convenent, since we can reuse the same (de)serializers, but conceptually it doesn't have to be that way.

This came up in the context of snapshotting in consensus, where extra containers allocation overhead is present during serialization of ledger state. See IntersectMBO/ouroboros-consensus#868 (comment)

First part of this ticket would be to implement a quick solution for Babbage, just so we can confirm that doing this change will actually be benefitial

[lehins]

There is a mostly complete implementation of this ticket in this branch: https://github.com/IntersectMBO/cardano-ledger/tree/lehins/use-mempack

@nfrisby have successfully confirmed that this results in a significant improvement to performance of snapshot creation: IntersectMBO/ouroboros-consensus#868 (comment)

We are now waiting for IntersectMBO/cardano-base#506 to be merged and new version of cardano-crypto-class to be released to CHaP. This is currently blocked by #4699