add dao which takes care about all CRUD operations on storage
remove blockchain state since everything is stored on change
remove storage operations from structs(entities)
move structs to entities package
pkg/rpc/neoScanBalanceGetter.go:54:56: method parameter assetIdUint should be assetIDUint
pkg/rpc/neoScanBalanceGetter.go:62:3: var assetId should be assetID
pkg/rpc/server_test.go:27:5: var testRpcCases should be testRPCCases
pkg/rpc/txTypes.go:19:3: struct field assetId should be assetID
pkg/rpc/txTypes.go:39:35: interface method parameter assetId should be assetID
pkg/rpc/types.go:115:2: struct field TxId should be TxID
Refs. #213.