NewMigratedStateStore returns an fsm whose functions will fail until the migration state says its ready.

NewVersionedStateStore sets takes a datastore, fsm parameters, migrations list, and target version, and returns an fsm whose functions will fail till it's migrated to the target version and a function to run migrations.

StateStore is a wrapper around a datastore for saving CBOR encoded structs.

StoredState is an interface for accessing state.