[css-inline-3] A property to exclude an element from the baseline calculation

[kizu]

I just published a blog post in which I talk about a technique that I use for fixing a baseline of button-like elements with icons for around twelve years already: https://blog.kizu.dev/fixing-baselines/

The post outlines the problem, but the gist: currently, we are only able to control if we're using the first or last baseline sets for the baseline source.

In flow layout, we can also use floats to exclude some elements from the baseline. I have this ancient CodePen from 2014 that demonstrates this: https://codepen.io/kizu/pen/eYyBMP

Proposal: add something like baseline-presence with an exclude value that could be used to, well, exclude some element from the baseline calculation.

Then, this property could be used on icons or other elements whenever we want to control the baseline more precisely than just setting the baseline-source.