Expand test suite with chart-llm specs dataset

[jonmmease]

@hyungkwonko just released a dataset of 1981 Vega-Lite specifications that cover a wide range of chart types, including composite views with interactivity. These are included in the hyungkwonko/chart-llm repository.

It would be great to add these to our integration test suite (which currently consists of specs derived from the Vega-Lite, Vega, and Altair galleries).

There is an explorer for the visualizations at https://hyungkwonko.info/chart-llm/explorer.html