Add title to the API workflow json. (#2380)

* Add `title` to the API workflow json.

* API: Move `title` to `_meta` dictionary, imply unused.

web/scripts/app.js

@@ -1784,6 +1784,10 @@ export class ComfyApp {
 				output[String(node.id)] = {
 					inputs,
 					class_type: node.comfyClass,
+					// Ignored by the backend.
+					"_meta": {
+						title: node.title,
+					},
 				};
 			}
 		}