Bugfix finds by valere 5

- bug fix: list blocks should display something useful
- enhancement: serialize/deserialize a vault
  - some fields of the vault (status, statistics) are not persisted
  - block data is not persisted
Some may be, but the dicts don't necessarily match up to the parameters of the objects.

For instance, some of them the dict is structured differently; others some parameters are not named what the dict calls them; so we'd still end up with a mix.

Now, the case could be made for perhaps unifying stuff a little to allow that, and it's probably not far off...but that should probably be a separate PR.