fix(axes): start of week label on multilayer time axis

[nickofthyme]

Summary

This PR resolves confusion around the start day of week labeling near the end of the month.

Before

After

Details

Currently the raster layer intervals are computed using a lower bound (i.e. minimum) and upper bound (i.e. supremum). This supremum value is used, in part, to determine how long we stick the axis label before clipping it off the screen. In the case of this issue, the start day of the week sticks past the given month into the next creating confusion.

This PR is a partial solution to clamp the start day supremum between the binStart and the end of the given month. This solution works fine for static timeslip axes but when looking at the dynamic timeslip chart, we may run into issues where the tick label is longer than the available space, causing strange positioning with disappearing text.

With this fix we also lose the context of the previous interval bin start. A future improvement of this logic is described in #1934 (comment).

Implementation changes

This PR adds a new property to the Interval type called labelSupremum. This property is used as a false supremum only for purposes of label text placement. Changing the logic for the supremum would have created a conflict between the actual supremum and that used only for text resulting in a broken interval logic and scale marker logic.

Issues

Fix for elastic/kibana#148872

Partially solves #1934

Checklist

• The proper chart type label has been added (e.g. :xy, :partition)
• The proper feature labels have been added (e.g. :interactions, :axis)
• All related issues have been linked (i.e. closes #123, fixes #123)
• New public API exports have been added to packages/charts/src/index.ts
• Unit tests have been added or updated to match the most common scenarios

[markov00]

I like the logic of adding an additional prop to handle the label space.
The logic needs to be fixed also on the xy_chart (probably already in progress locally, but not written in the TODO list)
For the xy_chart configuration, you could use the Area->Timeslip storybook example, and change the knobs configurations (like in the attached screenshot) to get the March 28th 2022 label that overlaps the April 2022. The 28th label should be removed by this fix.

[nickofthyme]

@markov00 Thanks, I fixed the xy_chart issue in 266b457. It's strange to me that only the continuousTimeRasters is shared between the timeslip and the xy_chart axis implementation, where there appears to be a bit of duplicate code higher in the render path. Maybe this could be improved in the future.

[markov00]

Changes look good but I have a hard time understanding why in some stories the 2 layers become a single layer (with overlapping text).
Also, this doesn't looks great axis-stories/uses-proper-english-ending-at-a-weekly-resolution.png because it seems that we reduced the frequency of the unlabelled months from 1 line every month to one line every 4 months

[nickofthyme]

buildkite update screenshots

[markov00]

It looks fine to me now, one last small thing: it will be great to have a screenshot for just that particular configuration, so it's easier to understand rather then trying to detect the problem from the small multiple screenshot changes

[nickofthyme]

buildkite update screenshots