Report error code contained in PlayReady licenser server response body
Created by: jeffcunat
When we get an error response from the PlayReady licenser server, it is a SOAP response. So we parse the response to look for a Fault tag in the SOAP response and extract a status code, a fault string and a possible message to build the string response of the getErrorResponse function
Moreover the response can also be sent with an HTTP 200 Response code. So the getLicenseMessage function returns null if a Fault tag is found in the SOAP response and in this case, we call the getErrorResponse function to get the error message
I have added some unit tests for this PR