[Lens] Allow Lens pie chart to order columns based on data

[flash1293]

Currently Lens pie chart slices are always ordered by its size. In some cases, this can be confusing (e.g. if the user explicitly specified alphabetical ordering for the top values function).

As it's not a common practice to order pie charts any other way than by size, the current behavior should stay the default behavior. To allow the user to override it, there should be a toggle in the dimension editor "Order slices by size" which defaults to on (making the non-standard behavior opt-in for rare cases where it's necessary).

This requires changes on elastic-charts because it's not possible to configure the order of slices from the outside: elastic/elastic-charts#1012

[elasticmachine]

Pinging @elastic/kibana-app (Team:KibanaApp)

[stratoula]

Available in recent versions