Better error handling in htpasswd

CSP handling is now separate, and the MQ return codes are tidied up.
Also added defaultIdentityTest to JMS tests and fixed copyright dates for htpasswd code

incubating/mqadvanced-server-dev/install-extra-packages.sh

@@ -1,6 +1,6 @@
 #!/bin/bash
 # -*- mode: sh -*-
-# © Copyright IBM Corporation 2019
+# © Copyright IBM Corporation 2019, 2021
 #
 #
 # Licensed under the Apache License, Version 2.0 (the "License");