Feature legend position

[xsahil03x]

#2 This PR adds a new property legendPosition in the widget, which enables positioning legend around the pie chart.

legendPosition: LegendPosition.right

enum LegendPosition {
  top,
  bottom,
  left,
  right,
}

[apgapg]

@xsahil03x ye close kyu kar dee?

[xsahil03x]

Are jo abhi merge kiye vo change bhi a rhe the isme.... Tabhi pehle vo merge hui ab dobara bhejta hu.