External dataset (#1485)

* fix: revert version

* feat: external collection

* import context

* external ui

* doc

* fix: ts

* clear invalid data

* feat: rename sub name

* fix: node if else edge remove

* fix: init

* api size

* fix: if else node refresh

packages/service/core/dataset/schema.ts

@@ -89,7 +89,8 @@ const DatasetSchema = new Schema({
         default: 'body'
       }
     }
-  }
+  },
+  externalReadUrl: String
 });
 
 try {