Validator: warn when name equals alt_name

[Famlam]

I stumbled upon ​this way (and some nearby ways with the same name). I cannot tell whether it's a common issue worldwide, or something very rare (and thus not worth adding), but perhaps the validator can catch cases where the value of name equals the value of alt_name?

Here it was introduced due to an alternative spelling (Leijenseweg rather than Leyenseweg) being used on traffic signs, which was reverted to Leyenseweg a few months later by someone in a commit called "Validatortest".