Centralize retained widget node destruction

src/canvas_modes.cpp

@@ -1778,6 +1778,6 @@ void CanvasModeFloodFill::enter(kCanvasMode prev)
 
 void CanvasModeFloodFill::leave(kCanvasMode next)
 {
-    m_tool->destroy();
+    pp::panopainter::destroy_legacy_node(*m_tool);
     m_tool = nullptr;
 }

src/node_checkbox.cpp

@@ -1,5 +1,6 @@
 #include "pch.h"
 #include "log.h"
+#include "legacy_ui_overlay_services.h"
 #include "node_checkbox.h"
 #include "texture.h"
 
@@ -103,7 +104,7 @@ void NodeCheckBox::set_icon(const std::string& icon_path)
     if (icon_path.empty() || !TextureManager::load(icon_path.c_str()))
     {
         if (m_icon)
-            m_icon->destroy();
+            pp::panopainter::destroy_legacy_node(*m_icon);
         m_icon = nullptr;
         return;
     }