PROTON-2867 Wrap the driver assertions in a thread local error

Ensure the error thrown shows the actual location of the test driver
method that throws the assertion making it easier to see where in the
unit tests the assertion comes from.

protonj2-test-driver/src/main/java/org/apache/qpid/protonj2/test/driver/AMQPTestDriver.java

@@ -850,7 +850,7 @@ private void processScript(ScriptedElement current) {
 
     private void checkFailed() {
         if (failureCause != null) {
-            throw failureCause;
+            throw new AssertionError(failureCause.getMessage(), failureCause);
         }
     }
 }