Added layer menu and layer list

src/DrawingProgram/Layers/DrawingProgramLayerManager.hpp

@@ -0,0 +1,17 @@
+#pragma once
+#include "DrawingProgramLayerListItem.hpp"
+#include "DrawingProgramLayerManagerGUI.hpp"
+
+class DrawingProgramLayerManager {
+    private:
+        DrawingProgram& drawP;
+        friend class DrawingProgramLayerManagerGUI;
+        NetworkingObjects::NetObjOwnerPtr<DrawingProgramLayerListItem> layerTreeRoot;
+
+    public:
+        DrawingProgramLayerManager(DrawingProgram& drawProg);
+        void init();
+        void write_components_server(cereal::PortableBinaryOutputArchive& a);
+        void read_components_client(cereal::PortableBinaryInputArchive& a);
+        DrawingProgramLayerManagerGUI listGUI;
+};