Move XUnit tests so they build and run under manualTests

manualTests/build.gradle.kts

@@ -59,7 +59,8 @@ sourceSets {
                 "**/services.x",
                 "**/reflect.x",
                 "**/regex.x",
-                "**/tuple.x"
+                "**/tuple.x",
+                "**/xunit_test.x"
             )
         }
     }

manualTests/src/main/x/xunit/xunit_test.x → manualTests/src/main/x/xunit_test.x

@@ -39,6 +39,7 @@ module xunit_test.xtclang.org {
         Int  passed = 0;
         Int  failed = 0;
 
+
         if (clz.is(Test)) {
             if (clz.group == Test.Omit) {
                 return passed, failed;

manualTests/src/main/x/xunit/xunit_test/engine_tests/AssertingExectionListener.x → manualTests/src/main/x/xunit_test/engine_tests/AssertingExectionListener.x

@@ -246,7 +246,7 @@ class AssertingExecutionListener
                     .assertCompleted()
                     .assertResult(result -> {
                         assert result.status == Failed;
-                        assert result.exception.is(errorType);
+                        assert result.exception.is(errorType) as $"expected exception {errorType} but caught {result.exception}";
                         assert result.duration != Duration.None;
                         });
         }