Add Range Bar Series demo to IGDataChart category series gallery

[Copilot]

This PR adds a WPF sample demonstrating the new RangeBarSeries introduced in v26.1.20261.14, aligned with the existing DataChart sample structure and series gallery patterns.

• Sample integration (IGDataChart category gallery)

  • Extended GalleryCategorySeries to include a new selectable demo entry for Range Bar Series.
  • Added a new RangeBarChart view in GalleryCategorySeries.xaml using:
    • NumericXAxis (value axis)
    • CategoryYAxis (category axis)
    • two RangeBarSeries instances to show range comparisons (Coal vs Oil, Hydro vs Nuclear).

• Localization/resource updates

  • Added XWDC_CategorySeries_RangeBarSeries to:
    • DataChartStrings.resx
    • DataChartStrings.ja.resx
    • DataChartStrings.Designer.cs
  • Wired the new resource into gallery sample registration in code-behind.

• Representative implementation

<ig:RangeBarSeries ItemsSource="{Binding EnergySampleData}"
                   HighMemberPath="Coal" LowMemberPath="Oil"
                   Title="{Binding StringEnergyCoalVsOil}"
                   XAxis="{Binding ElementName=RangeBarXAxis}"
                   YAxis="{Binding ElementName=RangeBarYAxis}"
                   Style="{StaticResource InteractiveSeries}" />

• • UI screenshot is not included: the available capture URL points to a browser-blocked page (ERR_BLOCKED_BY_CLIENT) rather than the rendered WPF sample.