checkBelgianBBAN function
Used for Belgian BBAN check
@ignore
Implementation
bool checkBelgianBBAN(String bban) {
final String stripped = bban.replaceAll(RegExp(r'[\s.]+'), '');
final int checkingPart =
int.parse(stripped.substring(0, stripped.length - 2), radix: 10);
final int checksum = int.parse(
stripped.substring(stripped.length - 2, stripped.length),
radix: 10);
final int remainder = checkingPart % 97 == 0 ? 97 : checkingPart % 97;
return remainder == checksum;
}