Centralize retained popup panel closing

src/node_panel_color.cpp

@@ -1,6 +1,7 @@
 #include "pch.h"
 #include "log.h"
 #include "node_panel_color.h"
+#include "legacy_ui_overlay_services.h"
 #include "canvas.h"
 
 Node* NodePanelColor::clone_instantiate() const
@@ -66,10 +67,7 @@ kEventResult NodePanelColor::handle_event(Event* e)
     case kEventType::MouseUpL:
         if (!m_mouse_inside)
         {
-            mouse_release();
-            m_parent->remove_child(this);
-            if (on_popup_close)
-                on_popup_close(this);
+            pp::panopainter::close_legacy_popup_panel(*this, on_popup_close);
         }
         break;
     default: