FIX estimator HTML repr force dark or light color

[rouk1]

Closes #30357

This PR changes the way color are chosen when displaying an estimator as an HTML representation.
The strategy is the following:

1. check if user uses vs code and their theme declares as light or dark
2. check if user uses jupyter in dark or light mode
3. check the default color of text that the element inherits from its hierarchy, use a luma threshold to determine if it dark or light
4. fallback to system media query

UI previews:

VS code light

VS code dark

VS code dark high crontrast

[github-actions]

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[ogrisel]

This looks good to me, but we do not have infrastructure for automated non-regression testing for this kind of fixes. Setting up some WebDriver based user testing could be a good idea (famous last words) but should better be deferred to a follow-up PR.

[jeremiedbb]

check if user uses jupyter in dark or light mode

I tested that case and it works as expected

[glemaitre]

I tested in VS Code and application that embed the estimator and it works as expected

[ogrisel]

Actually it does not look similar to the preview of the description of the PR for me:

[ogrisel]

Actually when not unfolding the inner element, this is fine as in the description so this is another unrelated problem.