Highlight position in `chartValueSelected` is always 0 / nan

* [x] I've read, understood, and done my best to follow the [*CONTRIBUTING guidelines](https://github.com/jjatie/Charts/blob/master/CONTRIBUTING.md).

## What did you do?
Created a basic LineChartView, implemented the `chartValueSelected` of the `ChartViewDelegate`.

## What did you expect to happen?
I want to get the xPx and yPx values of the highlight to place a custom UIView on top of the chart at the highlighted position

## What happened instead?
The `chartValueSelected` gets called successfully, but I get weird values for all the positions:
(`highlight.drawX`, `highlight.drawY`) = (`0.0`, `0.0`)
(`highlight.xPx`, `highlight.yPx`) = (`nan`, `nan`)

When setting a breakpoint inside the init method (the one with xPx and yPx) of the Highlight class - the xPx and yPx parameters passed into it are correct. But I assume I'm getting a different Highlight object in the `chartValueSelected` method (the one that's called from `ChartViewBase` -> `highlightValue()`, without xPx and yPx)

## Charts Environment

**Charts version/Branch/Commit Number:*4.1.0*
**Xcode version:*14.0*
**Swift version:*5*
**Platform(s) running Charts:*iOS*
**macOS version running Xcode:*Ventura*

## Demo Project
I don't have a demo project, but can provide it if needed. Currently I just want to verify if it's a global issue

Start in ChartViewBase at highlightValue() and trace the Highlight object passed to chartValueSelected in ChartViewDelegate. Compare that object with the Highlight initializer that receives xPx and yPx; done means the callback exposes the selected highlight's correct drawX, drawY, xPx, and yPx values on iOS.

Written by the indexing model from the issue text.