[TASK] Migrate theme to light dark notation

With new web standards arising and getting shipped to the web platform,
we are migrating the currently limited light and dark mode components to
the web native color-scheme.

See: https://developer.mozilla.org/en-US/docs/Web/CSS/color-scheme

Instead of relying on preferred color scheme queries, we're adopting the
light-dark color function, streamlining our CSS and ensuring compatibility
with all major browsers, except Safari (for now).

While Safari is slightly behind, we anticipate full support for
light-dark mode by May 2024, with the feature already available in
Safari 17.5 Beta.

See: https://developer.mozilla.org/en-US/docs/Web/CSS/color_value/light-dark
See: https://developer.apple.com/documentation/safari-release-notes/safari-17_5-release-notes

Note:

Safari users will experience missing backgrounds and colors due to our
decision not address this behavior. We're forward-facing and planning
for the LTS release. If you intend to use Safari during development,
please ensure you're using at least Safari 17.5 Beta.

We're monitoring the situation closely and will implement a fallback if
Safari hasn't released a compatible version before 13.2.

Resolves: #103705
Releases: main
Change-Id: I9f53e992f4d55efd86420a72a84da9d90b16e490
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/83995


Tested-by: Andreas Kienast <a.fernandez@scripting-base.de>
Reviewed-by: Benjamin Franzke <ben@bnf.dev>
Tested-by: Benjamin Franzke <ben@bnf.dev>
Reviewed-by: Andreas Kienast <a.fernandez@scripting-base.de>
Tested-by: core-ci <typo3@b13.com>
Reviewed-by: Frank Nägler <frank.naegler@typo3.com>
Tested-by: Frank Nägler <frank.naegler@typo3.com>
Tested-by: Benjamin Kott <benjamin.kott@outlook.com>
Reviewed-by: Benjamin Kott <benjamin.kott@outlook.com>