Added candlestick chart type - added QCandlestickSeries - added QCandlestickSet - added QCandlestickLegendMarker - added model mappers - added Candlestick, CandlestickChartItem, CandlestickData - added SeriesTypeCandlestick to SeriesType enum - added LegendMarkerTypeCandlestick to LegendMarkerType enum - added candlestick chart example - added QML candlestick chart example - added candlestick tester - added autotests - added documentation [ChangeLog][CandlestickChart] Added new chart type: Candlestick Chart. Task-number: QTBUG-50544 Change-Id: I17d18dfa23e0ea209bf51ab1e349585b9cb50a8f Reviewed-by: Miikka Heikkinen <miikka.heikkinen@qt.io>