[stats/computeStats] min/max should match the dataset when there are no outliers

[williaster]

Noted in #841:

When there are no outliers, min/max should be the Math.min(data) and Math.max(data) of the passed data. Currently min/max are always computed as the low (Q₁ - 1.5 * IQR) & high (Q₃ + 1.5 * IQR) values which are used for calculating the outliers. These are the min/max when showing outliers, but shouldn't be used when there are no outliers.

For example:

data = [10000, 2400, 10000, 10000]
computeStats(data).boxPlot;
{
  "min": 500,
  "firstQuartile": 6200,
  "median": 10000,
  "thirdQuartile": 10000,
  "max": 15700,
  "outliers": []
}

The expected output should be

{
  "min": 2400,
  "firstQuartile": 6200,
  "median": 10000,
  "thirdQuartile": 10000,
  "max": 10000,
  "outliers": []
}