Add validation for Pakistan TIN

[unho]

It is called National Tax Number (or NTN for short, نیشنل ٹیکس نمبر in Urdu). It is 7 digits plus a check digit. Format is like 1234567-8.

• https://www.oecd.org/tax/automatic-exchange/crs-implementation-and-assistance/tax-identification-numbers/Pakistan-TIN.pdf
• Get check digit online for a NTN without it (also provides company name for quick validation): https://e.fbr.gov.pk/NTNCheckDigit.aspx
• https://propakistani.pk/how-to/how-to-get-ntn-verified-online/
• http://demoen.tindb.cz/country-pk.html
  • Says it is 7 digits + 1 check digit, with the format 0000000-0.
• https://world.salestaxhandbook.com/pk-pakistan
• https://tin-check.com/en/pakistan/

Online search:

• https://e.fbr.gov.pk/esbn/Verification?PID=e35mmWrJKMV1u9Kvqk6agw==#

Examples:

• Thousands of examples in "Active Taxpayer List (Income Tax)" link in https://www.fbr.gov.pk/categ/active-taxpayer-list-income-tax/51147/30859/71169
  • Or direct link to it https://www.fbr.gov.pk/Downloads/?id=3901&Type=Docs
  • Note this XLSX contains both CNIC for individuals and NTN for companies, so scroll down!
• Found on the Internet:

  3804142-1
  0801599-6
  0816469-0
  0698343-0
  0711795-7
  0801380-2
  2217220-3
  2168117-1
  0700271-8
  0711545-8
  2138500-9
  3027108-8
  0785983-0
  4368251-7
  1347561-4
  1543137-1
  0710060-4
  0658560-4
  0712242-0
  0698049-0
  2261899-6
  0710672-6
  1268238-1
  1496632-8
  0698202-6
  3004934-2
  0822910 - 4
  0660564-8
  2544314-3
  0657297-9
  0698187-9
  1158490-4
  0658678-3
  0912725-9
  1143539-9
  0711554-7
  0712418-0
  0999468-8
  2180652-7
  0711167-3
  0712140-7
  0709930-4
  0801137-7
  1868111-5
  0820781-0
  0709782-4
  0698190-9
  0711982-8
  0712821-5
  0676546-7
  0711020-7
  7443848-2
  0698469-0
  1688091-9
  3123405-4
  0815616-6
  1319140-3
  7757795-2
  3072746-4
  0133480-8
  2663705-7
  0657139-5
  0709694-1
  3093299-8