* [DEV-378] Added feeAccumulator structures
* [DEV-378] Added logic to create and store fee data when validating a block
* [DEV-378] Renamed feeAccumulator to compactFeeData, and all related entities accordingly
* [DEV-378] Converted MsgTx.TxHash() to pointer to hash and not hash
* [DEV-378] Restructured parameters to buildFeeTransaction and related entities
* [DEV-378] Finished the code that calculates fees for blocks
* [DEV-378] Fix TxIndex after changing the structure of AcceptedTxsData
* [DEV-378] For genesis block: Return empty AcceptedTxsData instead of nil
* [DEV-378] Off-by-one error
* [DEV-378] Length of compactFeeData should be determined by specific method, not
* [DEV-378] Multiple bugfixes in tx fee calculation
* [DEV-378] Calculate fee even if fastAdd, to save feeData
* [DEV-378] use IsEqual instead of == when comparing TxHash
* [DEV-378] txindex: if including block is the new block - don't fetch id from DB
* [DEV-378] Fixed a few typos and made some vars consts
* [DEV-378] Re-organized fee functions, removed redundant functions and constants, and revised a few comments
* [DEV-378] Recovered fmt string changes lost in merge
* [DEV-378] Renamed acceptedTxsData and related types and vars to txsAcceptanceData
* [DEV-378] Some comment fixes
* [DEV-378] Remove redundant .ToString()
