Match a statement to an account

What your assistant is told

Call this FIRST when the user gives you a bank statement: pass the IBAN printed on it. If an account has that IBAN, it is returned in account — import into it. If NONE does, do not import yet and do not guess: accountsWithoutIban are the user's accounts that have no IBAN (the statement may be one of them) and suggestedAliases are names on offer for a new account, the IBAN's last 4 digits first. Ask the user which it is. If it's an existing account, update_account with this iban; if it's new, create_account with this iban and the alias they choose (or omit alias to use the last 4 digits). Then import with log_transactions_batch. Read-only.