Merge branch 'webservice-refactor' into 'master'

Refactor 'webservice' ZMQ server

See merge request detectors/pycalibration!441

webservice/messages.py

@@ -13,6 +13,7 @@ class Errors:
     MDC_RESPONSE = "FAILED: Response error from MDC: {}"
     NOT_CONFIGURED = "FAILED: instrument not configured, please contact det-support@xfel.eu"
     NOT_SUBMITTED = "FAILED: correction of {} failed during submision, please contact det-support@xfel.eu"
+    OTHER_ERROR = "FAILED: Error {}, please contact det-support@xfel.eu"
 
 
 class MDC: