Animate FlDotData

I want to apply a bouncing animation to the last dot of a LineChart. Currently, FlDotData only accepts DotPainter. Therefore, to animate it, I will need to use setState, which will redraw the chart so it's not good for performance

**Describe alternatives you've considered**
- Can I get the location on screen of a spot? then I can place another Widget above on LineChart within a Stack, then I can animate on this Widget?

Start by reviewing the FlDotData and LineChart APIs to understand how dot painters are configured and how chart updates are triggered. Define an approach for animating the last dot without requiring setState to redraw the chart, and verify that the resulting API supports the requested bouncing animation.

Written by the indexing model from the issue text.