Bank Account Number masking; changed masking logic for Fiji and Papua New Guinea

Previously Bank Account Numbers for Fiji and Papua New Guinea were masked by replacing some characters with "?".

This masking logic has been updated and standardised as follows:

1. Mask character updated from "?" to "*".

2 A maximum of four digits on the left and four digits on the right are shown, but at least 4 digits are always masked.

3 If the Account Number is less than 8 characters, extra mask characters are added to make the mask Account Number 8 characters.