Custom DataLabel

[Enigmatrix]

Is your feature request related to a problem? Please describe.
I would like a way to create a per-data point DataLabel that isn't just text. I know there are some ways of doing this e.g. custom LabelGeometry for a Series, but there is not way to pass the point itself to them, only a string.

Describe the solution you'd like
The ILabelGeometry<TDrawingContext> having a object DataPoint property. This is likely fine since the default implementor, LabelGeometry, won't use it, but it will allow those wanting to customize their derived LabelGeometry with something more than just a string to base their OnDraw on. They can cast it to the expected type accordingly.

Describe alternatives you've considered
The other option would be having this DataPoint property be of a generic type (so modify ILabelGeometry to ILabelGeometry<TModel, TDrawingContext>). It might not be so bad, especially since for PieSeries<TModel, TVisual, TLabel>, the constraint for TLabel can be where TLabel: ILabelGeometry<TModel, TDrawingContext>, class instead of the current where TLabel: ILabelGeometry<TDrawingContext>, class. Or we can use ChartPoint for DataPoint as well.

Additional context
Trying to create a custom PieChart similar to LiveCharts v1

[beto-rodriguez]

There is finally an example to fix this:

https://github.com/beto-rodriguez/LiveCharts2/blob/dev/samples/ViewModelsSamples/Pies/Icons/ViewModel.cs

I will close this for now, since this is actually supported in older versions of the library, this sample will be in the website soon.

Thanks for the report.