This API gother information about messages passing in the system, in
this patch the following API will be supported:
/messaging_service/messages/replied
/messaging_service/messages/sent
/messaging_service/messages/pending
/messaging_service/messages/exception
/messaging_service/messages/respond_pending
/messaging_service/messages/dropped
The swagger defintion can be retrieved from:
/api-doc/messaging_service
