Applies the range options to the HighChart chart instance.

Returns a options map with information about which range selector button is selected or what are the extremes currently set in the navigator. The result of this method can be passed into module:ct-chart/highchart/RangeUtility.applyOptions to re-apply the options (after deserialisation for example).

The returned map will always have the following structure:

{
  selectedRangeSelector: null,
  extremes: {
    relativeMin: null,
    relativeMax: null
  }
}

Note that if selectedRangeSelector is not null then the extremes values will be null, and the other way around. They can however both be null.