Implement a way to prevent double statement of bank account numbers on cashflows

It's been common practice to include all or part of the account number on the bank definitions, and we don't want to have to change that. However currently the Cashflow pulls the Account Number from the Bank Def and adds an appended form to the header. This creates a duplication of the account number that's in the bank description that's unwanted.

There should be a header like there is for all other Financials components where this can be fixed. The current automatic use of the appended account number should flow to that header so it can be removed (or customized).