AutoTest: Add automatic run after build

Add an option to automatically run tests if the build
succeeded and the current project has tests.

Change-Id: I1fe028be84279b9b488f78590565c6d4b0449e34
Reviewed-by: David Schulz <david.schulz@qt.io>
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@qt.io>

src/plugins/autotest/testtreeitem.cpp

@@ -245,6 +245,8 @@ TestConfiguration *TestTreeItem::asConfiguration(TestRunMode mode) const
     case TestRunMode::Debug:
     case TestRunMode::DebugWithoutDeploy:
         return debugConfiguration();
+    default:
+        break;
     }
     return nullptr;
 }