Qt6 Migration: Merge latest Qt5 devel content and apply migration fixes

- Merged 292 changed files from dlbo snapshot
- Fixed IDL enum collisions (PortType, PdmEventType)
- Fixed Grantlee template for C++11 scoped enums
- Fixed CMake VERSION_GREATER syntax
- Added missing directories (THP, LtsRestClient, etc.)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Lts/Tools/RestClientUi/main_window.h

@@ -0,0 +1,38 @@
+#pragma once
+
+#include "LtsRestClient/lts_rest_client.h"
+#include <QJsonDocument>
+#include <QMainWindow>
+
+// Documentation on how to use it can be found at https://confluence-classified.rh-int.de/spaces/LEG/pages/207919552/HOWTO+RestClientUi+Tool
+
+namespace Ui
+{
+class MainWindow;
+}
+
+class MainWindow : public QMainWindow
+{
+  Q_OBJECT
+
+  public:
+  explicit MainWindow(QWidget *parent = nullptr);
+  ~MainWindow();
+
+  private slots:
+  void onGetClicked();
+  void onPostClicked();
+  void onPutClicked();
+  void onDeleteClicked();
+  void onClearResponseClicked();
+  void onExportResponseClicked();
+
+  private:
+  void loadRequestTemplates();
+  LtsCommon::LtsRestClient *createClient();
+  void showSuccess(const QJsonDocument &json);
+  void showError(const QString &error);
+  void highlightMethodButton(const QString &method);
+
+  Ui::MainWindow *ui;
+}; // class MainWindow