EDIValue(X(60)) is not limiting the string max length when serializing

Hi,

I was serializing a file and I realized that EDIValue(X(60)) is not limiting the string max length when serializing despite the fact that I indicated 60 in the attribute.

```c#
[EdiValue("X(60)", Path = "POD/2", Description = "POD03 - Proof of delivery name / Received by")]
public string ProofOfDeliveryName { get; set; }
```

Is there any reason why Edivalue attribute doesn’t validate string max length?

Use the provided C# model with EDIValue("X(60)") as the reproduction and trace how the attribute is handled during serialization. Add coverage for a value exceeding 60 characters; done means serialization enforces the declared maximum length without breaking the existing EDI behavior.

Written by the indexing model from the issue text.