Add del on state store account

[shuse2]

Description

account state store should have del function.

• del should check if exist in state store memory, and delete from there
• del should delete from the database using batch
• Add schema deleted: [{ key: string, value: Buffer }] to diff schema
• del should save the complete diff into deleted of the diff schema if existed in DB.
• When deleting block, it should restore the value to the database

Motivation

From the reclaim transaction, it requires the deleting of the account.

Acceptance Criteria

• All the scenario are covered in the unit test