DataSeries zIndex can't be set

[vaadin-bot]

Originally by @alvarezguille

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Originally reported in https://vaadin.com/forum#!/category/203413
In charts 2.* it was possible to set it in PlotOptions and then set the PlotOptions to a series.
It should be possible to set zIndex either through plotoptions or directly to the series

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Imported from https://dev.vaadin.com/ issue #19970

[emarc]

I'm facing this issue - missing zIndex from PlotOptionsLine.

Use case: trying to match the topmost line with the first color in my theme.

It's easily worked around by extending PlotOptionsLine and adding zIndex, but obviously it would be better to have support out-of-the-box.