[Feat] Integrate VegaFusion to move transforms out of the browser

[jonmmease]

Hi 👋 ,

Congrats on the pygwalker release. I'm the maintainer of VegaFusion, which is an open source project that provides server-side scaling for Vega visualizations by automatically extracting Vega transforms and evaluating them on the server. This makes it possible to scale many Vega/Vega-Lite visualizations to millions of rows as long as they include some form of aggregation.

I haven't looked at the architecture of pygwalker, but it might be fairly straightforward to integrate VegaFusion and enable pygwalker to support lager data sets. Let me know if you're interested in talking through details!