Empty string elements with XSD restrictions are deserialized as `null` instead of `""`

[kouak]

I've encountered an inconsistency in how empty XML elements are deserialized when XSD restrictions are involved.

When an element is defined as a simpleType based on xs:string with a restriction (such as xs:pattern), receiving an empty tag in the SOAP response (<myField></myField>) results in the value being deserialized as null.

The value should be deserialized as an empty string "", which is the behavior observed for fields defined without restrictions.