text: Title: [BUG] transform does not work for Fugue DataFrames
  Body: **Describe the bug**
  The problem is here https://github.com/fugue-project/fugue/blob/ff004917b48b31796f064cc390e1465efcd6cfd4/fugue/interfaceless.py#L67
  
  **Expected behavior**
  It should be `result`, otherwise it will just return the original dataframe
  
  **Environment (please complete the following information):**
   - Backend: pandas/dask/ray?
   - Backend version:
   - Python version:
   - OS: linux/windows
  