two response handlers:

• series_data: works with all vislib types except pie (line, area, bar, heatmap. metric, gauge, goal)
• hierarchical_data: works with pie chart

goals:

• decouple vislib from ES response (aggConfigs)
• decouple tooltips from ES response
• decouple event handling (filter, brush, hover) from ES response
• decouple <visualization> from ES response
• provide easy to use data format

as side effect two issues are fixed:
closes #12746
closes #10543

things that are still missing:

• tests for new response handlers

other charts should be converted to use one of the new request handlers as well, probably the third one will need to be added (table_data)

using visualizations is now fairly easy as the data object is no longer coupled to elastic search.

const myVis = new Vis(indexPattern, 'bar');
const myData = {
  charts: [{
    label: 'my chart label',
    series: [{
      label: 'Count',
      values: [{ x: 'a', y: 120}, { x: 'b', y: 80 }, { x: 'c', y: 140 }]
    }]
  }]
};

<visualization vis=myVis data=myData></visualization>