text: Title: Enhancement: Support custom response for batch actions
  Body: Enhance the @action decorator to support custom responses, such as redirects or rendering HTML pages, instead of just returning strings (related to #205)
  
  Todo: 
  - [x] Add a custom_response flag to the @action decorator function (default: False).
  - [x] Update submitAction() in [list.js](https://github.com/jowilf/starlette-admin/blob/main/starlette_admin/statics/js/list.js) to handle custom responses.
  - [x] Modify handle_action in the base admin class to support custom responses.
  - [x] Ensure backward compatibility.
  - [x] Include an example in [custom_actions example](https://github.com/jowilf/starlette-admin/tree/main/examples/custom_actions)
  - [x] Add tests.
  - [x] Update the documentation