Add validation for Faroe Islands TIN

[unho]

• It seems to be called V-tal and it is 6 digits long (for legal entities).
  • According to https://www.taks.fo/fo/borgari/bolkar/at-stovna-virki/ "v-tal" is short for "vinnutal".
• https://www.oecd.org/tax/automatic-exchange/crs-implementation-and-assistance/tax-identification-numbers/Faroe-islands-TIN.pdf
• https://www.sgbt.lu/fileadmin/user_upload/SGBT/PDF/Compliance/CRS_2018/TIN-UK.pdf
• https://www.sgbt.lu/fileadmin/user_upload/SGBT/PDF/Compliance/CRS_2018/20191031_TIN_Leaflet_EN.pdf
• http://heima.olivant.fo/~styrheim/tekst/uri/uri.html
• According to https://www.torshavn.fo/get.file?ID=349

  The “V-number” is the business’ “identity” and is used in nearly all business-related connections, such as the reporting of wages to the banks, tax forms, business bank accounts, etc.

• https://tin-check.com/en/faroe-islands/

Examples:

• https://ahandil.fo/handlar/

  602 590
  616 923
  557 692
  568 597
  568 031
  605 174

• https://www.apotek.fo/um-okkum/samband

  623857
  323853
  323853
  549118
  330833
  345490

• https://www.betri.fo/en/insurance/other-insurances/

  589306
  537.535
  563.609
  478 865
  537.543

• https://www.google.com/search?q=site:.fo+%22V-tal%22

  463000
  55 16 00
  345334
  403369
  630713
  369497
  623016
  636568
  322407
  538485
  452432
  339849
  489042
  328871
  324213
  552569
  575712
  328944
  504572
  322059
  308382
  502855
  554375
  33 28 28
  606294
  309273
  353477
  617105
  539813
  328863
  321079
  607436
  401900
  550558
  569682
  637114
  628980
  522821
  427888
  401900
  355216
  619558
  437.115
  603937
  355186
  476897
  366161
  620092
  546.089
  551.023
  408638
  498.289
  601470
  587974
  641154
  636223
  488135
  619388
  625485

• https://www.google.com/search?q=site%3A.fo+%22vtal%22

  627976
  576174
  576174
  403687
  401900
  625590
  374989
  623792
  623385
  585335
  331538
  613606
  597570
  589.810

• https://www.google.com/search?q=site%3A.fo+%22Vinnutal%22

  FO384941 (it is prefixed with Faroe Islands country code)

• https://www.google.com/search?q=%22V+number%22+%22faroe%22

  559679

• Found on the Internet:

  443921
  617121
  620785
  638722
  550612
  509078
  344338
  579319
  602221
  516244
  33 28 28
  379778
  604097
  578 509
  519324