fix(tooltip): Fix tooltip.format.value arg for bar range data

[netil]

Issue

#3507

Details

• Make format function called once for range(array) data type
• Update on defaultValueFormat to handle array type value also.

bb.generate({
  data: {
    columns: [
      ["data1", [100, 250], 30]
    ],
    type: "bar"
  },
  tooltip: {
    format: {
      value: function (value, ratio, id, index) {
        // when value is ranged type, "value" argument will be an array
        // x0: value => [100, 250]
        // x1: value => 30
      }
    }
  }
});

[coveralls]

coverage: 94.354% (+0.001%) from 94.353%
when pulling b6ea783 on netil:tooltipValue#3507
into 048c4e2 on naver:master.