Adds domain to pie trace in order to support subplots

[emilianbold]

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Description

Plotly supports pie chart subplots. This is doable by adding the domain info.

Testing

Manual testing. With this:

        PieTrace trace = PieTrace.builder(new Object[]{"A","B"}, new double[]{2.0, 1})
                .domain(Domain.builder().row(0).column(0).build())
                .build();
        PieTrace trace2 = PieTrace.builder(new Object[]{"A","B"}, new double[]{12.0, 21})
                .domain(Domain.builder().row(0).column(1).build())
                .build();
        PieTrace trace3 = PieTrace.builder(new Object[]{"A","B"}, new double[]{20.0, 10})
                .domain(Domain.builder().row(1).column(1).build())
                .build();

        Layout layout = Layout.builder()
                .grid(Grid.builder().rows(2).columns(2).build())
                .build();

        Figure f = new Figure(layout, trace, trace2, trace3);

we get this:

[benmccann]

Looks fine to me though Larry knows the plotting code much better than I do

[emilianbold]

I think an approval is enough. It's a minor change we can always revert if needed.