Refactor the file into multiple layers:

[jakub-wojciechowski]

1. Low level readings (stateDbReader): Db connection, prefixes, transformations (bufferHex, bufferToInt, buffer64, buffer256, sha3, atStruct, atMap, blockNumberByHash, blockHash, _blockHeader..... getNode)

2. Trie traversals (stateDbFinder): (_sfind, binarySearchCreation, findNextBlock, _errorCheck)

3. Data extractors (dbExtractor): (_getRange, getRange, getRangeMulti)

4. Query splitter: logic when we try to split the data range into chunks and execute them in parallel not to waste time waiting for IO db operations (btw. is there a n value that brings the bests results?)

5. High level api to provide one function per one method used (simple, hash, lastPath) - taken from /test/samples.

[adamjabone]

Done. Every layer is extension of lower layer.