VueUi3dBar stack mode

VueUi3dBar was improved to display stacked bars when the series dataset option is used.
Stack mode is automatically enabled when the series attribute is present in the dataset:

const dataset = {
  series:  [
    {
      name: string,
      value: number,
      color?: string
      // Adding breakdown array will display donuts in the legend portion of the chart
      breakdown?: [
        {
          name: string,
          value: number
        },
        {...}
      ]
    },
    {...}
  ]
}