feat(WIP): chain data importer+exporter

[encody]

What ❔

Introduces the requisite functionality to create a chain with a custom genesis state:

• Export the state (storage logs, initial writes, factory dependencies) from a ZK chain database to a portable export file.
• Inject the state from such a file during the genesis of a new chain.

Why ❔

Migrating an application with large state to a ZK chain can be expensive if done via conventional means (i.e. performing a large set of import transactions over many batches). It is much cheaper to spin up a chain with a custom genesis state instead.

Checklist

• PR title corresponds to the body of PR (we generate changelog entries from PRs).
• Tests for the changes have been added / updated.
• Documentation comments have been added / updated.
• Code has been formatted via zkstack dev fmt and zkstack dev lint.