tax_code missing results in tripple duplicated VAT lines

[BorisKamp]

Hey!

See here:
#5540

@shahednasser asked me to create an issue.

I created a custom tax provider but forgot to set the tax_code in the medusa interface:

This resulted in some order having trippled VAT lines. Why is this field not enforced as required in the medusa interface?

When I try to edit the rate, the VAT code is enforced. Somehow I ended up having null for the code after creating the new tax provider. Is this something you guys are aware of?

See here on my production medusa, my code is empty....