This pull request introduces a database tool for inspecting the state history.
It can be used for either account history or storage slot history, within a
specific block range.
The state output format can be chosen either with
- the "rlp-encoded" values (those inserted into the merkle trie)
- the "rlp-decoded" value (the raw state value)
The latter one needs --raw flag.
rjl493456442