Integrate queryStakePoolDefaultVote

[smelc]

Context

We recently augmented query spo-stake-distribution to include the DRep delegation choices of the pools' rewards accounts. This was #990 which is doing multiple queries in a row. This implementation is temporary, because ultimately we can use a dedicated ledger query: queryStakePoolDefaultVote, implemented here: IntersectMBO/cardano-ledger#4735

This issue keeps track of removing the complex code written for #990 and replace it with a call to the new ledger query.

Status

This issue is blocked on having consensus integrate the new queryStakePoolDefaultVote here: https://github.com/IntersectMBO/ouroboros-consensus/blob/main/ouroboros-consensus-cardano/src/shelley/Ouroboros/Consensus/Shelley/Ledger/NetworkProtocolVersion.hs

[edit] consensus created an issue tracking the required addition: IntersectMBO/ouroboros-consensus#1371