Define Huddle spec for all ledger state queries

Similarly to how we have huddle spec for on chain data, we also need to provide stable CDDL specification for all ledger state query.

Huddle spec of queries, just like onchain data, can chain from one era to another, so we also need per era spec. However, unlike onchain data, we do not need all of the historical specification available, so this work should start with Conway era, but be flexible enough to support future eras.

I propose the work of adding huddle spec for each query be split into separate PRs.