VAT number validation

[Tychodewaard]

Feature request: The VAT number validation checks the 2 letters of the VAT number to decide EU rules. What happens is that companies fill in their VAT number using just numbers. The country of origin is not detected and the VAT is not applied.

An enhencement would be to have a validation that checks whether the VAT number starts with letters. If not, the feedback should be 'The VAT number starts with letters' (translatable)