Fix blockchain:import / blockchain:export

[shuse2]

Description

blockchain:import and blockchain:export should pack all the necessary on-chain information.

- blockchain.db
- state.db

• compress/decompress are already done in the existing command, so it should follow the same way

Motivation

All on-chain information must be able to backup and restore with the command

Additional Information

Currently, export is compressing the blockchain.db from data path and outputs tar ball and import is decompressing the tar ball and outputting to the data path.