Fix bounds checks on binary search

[jjatie]

Issue Link 🔗

#4571

Implementation Details 🚧

Incorrectly returned index beyond the last valid index. This is now corrected

[InvaderZim62]

This change and possibly the changes leading up to it caused LineChartData(dataSets:) to stop plotting all data points, if the LineChartDataSet entries are not all the same size. Only the first point is plotted for the shorter data set. To reproduce, run this code:

let chart = LineChartView()
chart.data = LineChartData(
    dataSets: [
        LineChartDataSet(entries: [
            ChartDataEntry(x: 0, y: 0),
            ChartDataEntry(x: 10, y: 10),
            ChartDataEntry(x: 20, y: 20)
        ]),
        LineChartDataSet(entries: [
            ChartDataEntry(x: 0, y: 5),
            ChartDataEntry(x: 10, y: 15)
        ])
    ]
)

When I reverted back to the earlier commit 857db24 this code plots all five data points.