add self-rag (#1070)

### What problem does this PR solve?

#1069 

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

api/apps/dialog_app.py

@@ -31,8 +31,8 @@ def set_dialog():
     req = request.json
     dialog_id = req.get("dialog_id")
     name = req.get("name", "New Dialog")
-    icon = req.get("icon", "")
     description = req.get("description", "A helpful Dialog")
+    icon = req.get("icon", "")
     top_n = req.get("top_n", 6)
     top_k = req.get("top_k", 1024)
     rerank_id = req.get("rerank_id", "")
@@ -92,7 +92,7 @@ def set_dialog():
                 "rerank_id": rerank_id,
                 "similarity_threshold": similarity_threshold,
                 "vector_similarity_weight": vector_similarity_weight,
-                "icon": icon,
+                "icon": icon
             }
             if not DialogService.save(**dia):
                 return get_data_error_result(retmsg="Fail to new a dialog!")