much nicer can you confirm if this has an impact on performance

It's a bit faster, really small, what's save is serialize/deserialize to stream. I plan to make another class to handle rewards and to store rewards by pool id (in validation.cpp where rewards are redistributed)

@bvbfan is this still a work in progress? you can change the title when you feel it's ready to merge in

It's no more a WIP, rewards are two types, Commission and PoolReward they are stored separate from account history.

listaccounthistory rpc call remains unchanged for account history, it has txid and txn the difference is there is no empty txid anymore, it means when it has txid it's account history, Rewards type is split to Commission and PoolReward, also rewards have poolID.
Account:
owner
blockHeight
type (Rewards is not valid type anymore)
txn
txid
amounts
Reward:
owner
blockHeight
type (Commission or PoolReward)
poolID
amounts

this could break the app if the Rewards type does not exist anymore, can we name "PoolReward" back to "Rewards" so that the type still exists, and split commission out

so basically just PoolRewards -> Rewards

Added https://github.com/cakedefi/defichain-private/issues/63

@bvbfan after merging the other PR (for including UTXO) this has quite a few conflicts

Rebased.

All unit tests pass locally, changes not affect wallet at all.

@Bushstar can you test new approach?