Bank Transactions; added limited support for Bank Cheques

Limited support for Bank Cheques has been added. Note, this allows the user to enter that the Cheque is a Bank Cheque, but actually saves the transaction as a normal cheque, updating the Reference to be prefixed with "BC#".

The following facilities have been updated to allow a payment method of "Bank Cheque" to be entered:

Loan Payment wizard
New Deposit wizard
Bank Entry, for Transaction Type of Loan Payments and Deposit Additional Deposits only.

This is converted, when committed, to a Pay Type of "Cheque" and the reference is updated to "BC#" + reference entered. This also means the reference is limited to 7 characters instead of 10.

Therefore bank cheques can be identified by the Payment Type being "Cheque" and where the Reference starts with "BC#".

When Reporting, eg Bank Transaction List or Transaction List, use a Reference range of BC#-BC#z to show only Bank Cheques.