* [NOD-1461] Change the external api interface to not having anything besides DomainTransactions and DomainBlocks.
* [NOD-1462] Move external api types to a separate package.
* [NOD-1462] Clarify which model we're using in miningmanager.
* [NOD-1462] Extract coinbase data to its own struct.
* [NOD-1462] Add a comment above CoinbaseData.
* [NOD-1462] Fix the comment above CoinbaseData.
* [NOD-1458] Rename RestoreUTXOSet to RestorePastUTXOSet.
* [NOD-1458] Make CalculateAcceptanceDataAndMultiset take BlockGHOSTDAGData and nothing else.
* [NOD-1458] Make ConsensusStateStore's Update take ConsensusStateChanges instead of just UTXODiff.
* [NOD-1458] Add Tips() to ConsensusStateStore.
* [NOD-1458] Make all implementation structs private.
* [NOD-1458] Remove BlockAtDepth and add highHash to ChainBlockAtBlueScore.
* [NOD-1458] Rename CalculateAcceptanceDataAndMultiset to CalculateAcceptanceDataAndUTXOMultiset.
* [NOD-1458] Add a dependency to GHOSTDAGManager from ConsensusStateManager.
* [NOD-1458] Add ChooseSelectedParent to GHOSTDAGManager.
* [NOD-1458] Add DifficultyManager.
* [NOD-1458] Add PastMedianTimeManager.
* [NOD-1458] Add Hash() to Multiset.
* [NOD-1458] Add a dependency to ghostdagManager from blockProcessor.
* [NOD-1458] Add errors to all interfaces that need them.
* [NOD-1458] Uppercasify types in comments.
* [NOD-1458] Fix a bad comment.
* [NOD-1458] Fix a comment.
* [NOD-1458] Rename ChainBlockAtBlueScore to HighestChainBlockBelowBlueScore.
* [NOD-1458] Replace BlockAndTransactionValidator with an anonymous interface.
