SOAP 1.2 fault reason xml:lang attribute not properly parsed on client side

CXF-4790 fixed the subcode in the SOAP 1.2 faults. The patch for that included also a partial fix for having xml:lang attribute properly written on the message going on the wire (server response). The problem is that the xml:lang attribute is still not properly parsed on client side, so it's not possible to get the actual fault reason message locale using the saaj api on client side.