osmo-smdpp + es9p_client: HTTP status 204 is used for handleNotification

As SGP.22 states, the handleNotification endpoint uses HTTP status 204,
not 200 (due to its empty body).

Change-Id: I890bdbd3e1c4578d2d5f0367958fdce26e338cac

osmo-smdpp.py

@@ -481,6 +481,9 @@ class SmDppHttpServer:
     @rsp_api_wrapper
     def handleNotification(self, request: IRequest, content: dict) -> dict:
         """See ES9+ HandleNotification in SGP.22 Section 5.6.4"""
+        # SGP.22 Section 6.3: "A normal notification function execution status (MEP Notification)
+        # SHALL be indicated by the HTTP status code '204' (No Content) with an empty HTTP response body"
+        request.setResponseCode(204)
         pendingNotification_bin = b64decode(content['pendingNotification'])
         pendingNotification = rsp.asn1.decode('PendingNotification', pendingNotification_bin)
         print("Rx %s: %s" % pendingNotification)

pySim/esim/es9p.py

@@ -136,6 +136,7 @@ class HandleNotification(Es9PlusApiFunction):
         'pendingNotification': param.PendingNotification,
       }
     input_mandatory = ['pendingNotification']
+    expected_http_status = 204
 
 # ES9+ CancelSession function (SGP.22 section 6.5.2.10)
 class CancelSession(Es9PlusApiFunction):