Adds initial intermediate qt6 porting state

qt6-after/qt6-migrated-legatus/Lts/Plugins/AdvancedSymbology/asb_gui_plugin_interface.h

@@ -0,0 +1,19 @@
+
+
+
+#pragma once
+
+#include <QString>
+
+namespace AdvancedSymbology
+{
+class ForeignGuiInterface
+{
+public:
+  ForeignGuiInterface() = default;
+  virtual ~ForeignGuiInterface() = default;
+
+  static QString pluginName() { return QStringLiteral("AdvancedSymbology"); }
+};
+
+}