Add test case for merging roles on methods and types to errai-security.
Add client-side interceptor for security testing to completely decouple server and client interceptor tests.
Fix security interceptor test harness problem that was causing erroneous passing of some tests.
Marshall exceptions thrown by server-side bus services.
Fix test harness for BusCommunicationTests (was hiding test failure).
Fix BusCommunicationTest: was checking wrong message part for an error message.