Centralize retained color picker closing

src/node_dialog_picker.cpp

@@ -3,6 +3,7 @@
 #include "util.h"
 #include "app.h"
 #include "canvas.h"
+#include "legacy_ui_overlay_services.h"
 #include "node_dialog_picker.h"
 #include <stdlib.h>
 
@@ -59,10 +60,7 @@ kEventResult NodeColorPicker::handle_event(Event* e)
                 m_color_old1->m_color = m_color_old->m_color;
                 m_color_old->m_color = m_color_cur->m_color;
             }
-            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: