Unique multiple fields

[Hesesses]

Description

Would be nice if it would be possible to check if a row would be unique with multiple fields. For example
phone field needs to be unique together with firstname.

phone 12345 + firstname john
phone 12345 + firstname john
That would be invalid

phone 12345 + firstname john
phone 12345 + firstname mark
That would be valid

Describe the solution you'd like

If this rule is added to phone, you could add array of other fields as param
RxwebValidators.unique(['firstname')