Optimized format for saving series `data`

[nishikantparmariam]

Coming from reproducer in highcharts-for-python/highcharts-stock#65 (comment), it seems that even if data is passed as list of lists, it is always converted into list of dicts, that may not be the most optimized way to pass data to Highcharts JS layer because things like turbo/boost may not work.

Refer - highcharts/highcharts#20057 (comment).

[hcpchris]

Hmm. Given your comment in highcharts-for-python/highcharts-stock#65 (comment) , this suggests that there is a bug somewhere in the implementation. Because in a context where NumPy is present/available data points should be serialized to a list of lists unless the data point has a property configured that precludes that. This will require a bit more investigation.