Papua New Guinea; add support for Bank BSB and Bank Account validation

Added better support for Bank Account validation in Papua New Guinea.

This includes a separate BSB field and validation of the BSB.

The list of predefined Banks in PNG is:

ANZ, ANZ Banking Group
BPG, Bank of Papua New Guinea
BSP, Bank South Pacific
MAY, Maybank (PNG) Limited
NDB, National Development Bank
WBC, Westpac Banking Corporation