Centralize retained dialog cancel bindings

src/node_dialog_cloud.cpp

@@ -7,6 +7,7 @@
 #include "node_message_box.h"
 #include "app.h"
 #include "image.h"
+#include "legacy_ui_overlay_services.h"
 #include "platform_api/network_tls_policy.h"
 
 Node* NodeDialogCloud::clone_instantiate() const
@@ -30,9 +31,7 @@ void NodeDialogCloud::init_controls()
 {
     btn_ok = find<NodeButton>("btn-ok");
     btn_cancel = find<NodeButton>("btn-cancel");
-    btn_cancel->on_click = [this](Node*) {
-        destroy();
-    };
+    pp::panopainter::bind_legacy_click_destroys_node(*btn_cancel, *this);
     container = find<Node>("files-list");
     std::thread(&NodeDialogCloud::load_thumbs_thread, this).detach();
 }