Function bank_from_latest_snapshot_dir

pub fn bank_from_latest_snapshot_dir(
    bank_snapshots_dir: impl AsRef<Path>,
    genesis_config: &GenesisConfig,
    runtime_config: &RuntimeConfig,
    account_paths: &[PathBuf],
    debug_keys: Option<Arc<HashSet<Pubkey>>>,
    additional_builtins: Option<&[BuiltinPrototype]>,
    limit_load_slot_count_from_snapshot: Option<usize>,
    verify_index: bool,
    accounts_db_config: Option<AccountsDbConfig>,
    accounts_update_notifier: Option<AccountsUpdateNotifier>,
    exit: Arc<AtomicBool>,
) -> Result<Bank>

follow the prototype of fn bank_from_latest_snapshot_archives, implement the from_dir case