text: Title: Support Narwhals DataFrames including DuckDB relation and Dask. 
  Body: In https://github.com/panel-extensions/panel-graphic-walker/pull/22 I will add more support for more data sources to `panel-graphic-walker`. I add general DataFrame support via [Narwhals](https://github.com/narwhals-dev/narwhals) because its what we are going to do for param, panel and rest of HoloViz ecosystem I believe.
  
  With the PR above we will end up supporting
  
  ![image](https://github.com/user-attachments/assets/9c36c8cd-820f-468d-ba6d-123613efe0e1)
  
  It would be very nice with 
  
  - DuckDB Relation and Dask support in pygwalker.
  - General support for any Narwhals DataFrame type
  - The pygwalker database `Connector` being a support Narwhals DataFrame type. [Context](https://github.com/narwhals-dev/narwhals/issues/1289).
  
  
  