pyramid chart support and pyramid chart should be plotted based on the area

### What problem does this feature solve?

ehcarts have funnel series , but pyramid shape is not supported in echarts we have a requirement for pyramid chart and if u look at data point of each level , it is plotted based on "Area" . Frist data point "Stage #1" has 46.51% as the value , so it had occupied 46.51 percent of pyramid chart area , Here are the requirements 1) we need pyramid chart support from echarts 2)reverse option(meaning upside down of pyramid chart ) 3) each data point should take its area in the pyramid Chart

### What does the proposed API look like?

Here are the requirements
1) we need pyramid chart support from echarts
2)reverse option(meaning upside down of pyramid chart )
3) each data point should take its area in the pyramid Chart