tests: qemuxml2xml: Test status XML formatting and parsing
    
    Recently we've fixed a bug where the status XML could not be parsed as
    the parser used absolute path XPath queries. This test enhancement tests
    all XML files used in the qemu-xml-2-xml test as a part of a status XML
    snippet to see whether they are parsed correctly. The status XML-2-XML is
    currently tested in 223 cases with this patch.