CMakePM: Use UNINITIALIZED for -D<var>=<val> in Batch Edit

CMake is setting the UNINITIALIZED type if you forget to set the
type of a variable when you do it from command line.

Qt Creator was setting INTERNAL, which had the effect of not
being displayed in the UI at all, giving the impression that the
value has been dropped.

Change-Id: I9a6b487bf5062d288365938fd7ef99b49de42884
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

src/plugins/cmakeprojectmanager/cmakebuildconfiguration.cpp

@@ -519,7 +519,7 @@ void CMakeBuildSettingsWidget::updateButtonState()
                     break;
                 case CMakeProjectManager::ConfigModel::DataItem::UNKNOWN:
                 default:
-                    ni.type = CMakeConfigItem::INTERNAL;
+                    ni.type = CMakeConfigItem::UNINITIALIZED;
                     break;
                 }
                 return ni;