[Feature] Apply styling on a stack level for bar charts

[acsbendi]

What problem does this feature solve?

Currently, styling is applied to each individual series/data point, but there's no way to apply it to the whole stacked group. Therefore, some styling may look strange since the bar isn't considered as a whole when applying the styling.

The concrete example where it matters is borders, which cut into the bar.
This is how a dashed border looks on a stacked bar currently:

And this is how it should look:

What does the proposed API look like?

The simplest I can think of is to introduce a new optional field in BarItemStyleOption, which could change where the styling is applied, for example target?: 'stack' | 'series'.