Add the ability to select specific services by port / service name

[veewee]

Fixes #557

This allows for selecting specific ports / services in the WSDL:

https://github.com/php-soap/wsdl-reader/releases/tag/0.19.0

 EngineOptions::defaults($wsdl)
-     ->withPreferredSoapVersion(SoapVersion::SOAP_12)
+     ->withWsdlServiceSelectionCriteria(
+         ServiceSelectionCriteria::defaults()
+             ->withPreferredSoapVersion(SoapVersion::SOAP_12)
+             ->withServiceName('SpecificServiceName')
+             ->withPortName('SpecificPortName')
+     );