Refactor-out code dupe in response message parsing
Refactor-out code dupe in response message parsing

bkircher/ews-cpp,bkircher/ews-cpp,m-Schlitzer/ews-cpp,otris/ews-cpp,m-Schlitzer/ews-cpp,otris/ews-cpp,bkircher/ews-cpp,otris/ews-cpp,otris/ews-cpp,m-Schlitzer/ews-cpp