Pie Chart Connector Lines feature

[amirk3321]

Hello,

I added a new feature to fl_chart package. Now, developers can use FLConnectorLineSettings to configure line pointing the value for PieChartSectionData.

Example PieChartSectionData to draw connector line pointing the value:

PieChartSectionData(
  connectorLineSettings: const FLConnectorLineSettings(
          type: FLConnectorType.line,
          color: Color(0xFFD5E5EC), // use any color,
          length: "40%" // use any length
  ),
);

The line results:

The connectorLineSettings field in PieChartSectionData is nullable, so simply remove it if you don't want to use it.

The suggestions, bugs, or contribution to the enhancements of these lines would be greatly appreciated.

Thanks

Fixes #1731

[cogivn]

Hi @amirk3321, I also need this feature on my app.
Can we add more customization like ability to customize external labels? Something like this...
Thank you so much,

[imaNNeo]

You still have some formatting changes. For example here

[imaNNeo]

And here

[imaNNeo]

And here

[imaNNeo]

These changes caused some conflicts in your branch. Please revert all the formatting changes