Move GUI unit tests to cpp files

Tests/UnitTests/GUI/TestGUI.cpp

 #include "google_test.h"
-#include <QString>
 #include <QCoreApplication>
 #include <QAbstractItemModel>
 #include "Comparators.h"
 
-#include "TestAxesItems.h"
-#include "TestComboProperty.h"
-#include "TestComponentProxyModel.h"
-#include "TestComponentUtils.h"
-#include "TestCsvImportAssistant.h"
-#include "TestDataItems.h"
-#include "TestDataItemViews.h"
-#include "TestDetectorItems.h"
-#include "TestExternalProperty.h"
-#include "TestFitParameterModel.h"
-#include "TestFormFactorItems.h"
-#include "TestFTDistributionItems.h"
-#include "TestGroupItem.h"
-#include "TestGUICoreObjectCorrespondence.h"
-#include "TestGUIHelpers.h"
-#include "TestLayerItems.h"
-#include "TestLayerRoughnessItems.h"
-#include "TestLinkInstrument.h"
-#include "TestMapperCases.h"
-#include "TestMapperForItem.h"
-#include "TestMaterialModel.h"
-#include "TestMaterialPropertyController.h"
-#include "TestMessageService.h"
-#include "TestModelUtils.h"
-#include "TestMultiLayerItem.h"
-#include "TestOutputDataIOService.h"
-#include "TestParaCrystalItems.h"
-#include "TestParameterTreeUtils.h"
-#include "TestParticleCoreShell.h"
-#include "TestParticleDistributionItem.h"
-#include "TestParticleItem.h"
-#include "TestParticleLayoutItem.h"
-#include "TestProjectDocument.h"
-#include "TestProjectUtils.h"
-#include "TestPropertyRepeater.h"
-#include "TestProxyModelStrategy.h"
-#include "TestSaveService.h"
-#include "TestSavingSpecularData.h"
-#include "TestSessionItemController.h"
-#include "TestSessionItem.h"
-#include "TestSessionItemData.h"
-#include "TestSessionItemTags.h"
-#include "TestSessionItemUtils.h"
-#include "TestSessionModel.h"
-#include "TestSessionXML.h"
-#include "TestTranslations.h"
-#include "TestUpdateTimer.h"
-
-#ifdef BORNAGAIN_OPENGL
-#include "TestRealSpaceBuilderUtils.h"
-#endif
-
 int main(int argc, char** argv) {
     QCoreApplication app(argc, argv);
     Q_UNUSED(app);