Add support for Uruguay TIN

[unho]

• https://www.oecd.org/tax/automatic-exchange/crs-implementation-and-assistance/tax-identification-numbers/Uruguay-TIN.pdf

• Algorithm in page 71: https://www.agesic.gub.uy/innovaportal/file/1634/1/modelo_de_datos.pdf

• Check online: https://servicios.dgi.gub.uy/ServiciosEnLinea/dgi--servicios-en-linea--consulta-de-certifcado-unico

• Not actually sure if this is for Uruguay or Guatemala: http://www.sia.eurosocial-ii.eu/files/docs/1382966022-Uruguay%20Registro%20UnicoTributario.ppt

• Query entity data by RUC: https://www.agesic.gub.uy/innovaportal/v/1600/9/agesic/consulta-de-entidad-por-rut.html

Plenty of Uruguay RUT examples: http://www.ciu.com.uy/innovaportal/file/14782/2/pge-_empresas_adheridas_2013-07-09.pdf

Implementation examples:

• (scroll down to RUT validation): https://www.taringa.net/+ciencia_educacion/validar-cedula-uruguaya-en-java_hlkia
• https://www.lawebdelprogramador.com/foros/Visual-Basic.NET/1297379-Digito-Verificador-de-RUT-Uruguay.html
• http://estebancarle.blogspot.com/2017/08/validar-rut-uruguay.html