Convert codebase to use CSS logical properties for RTL support

Started working on this a bit with https://github.com/csstools/stylelint-use-logical

Used the --fix command to automatically convert the syntax.

Changes are pushed up to https://git.drupalcode.org/project/olivero/-/commits/css-logical-properties

Tugboat preview for this branch is at https://css-logical-properties-ugcf7gjd8lxjvfdkwe13zx5h0jaqn5hl.tugboat.qa/

The preview is fairly broken in the latest stable Chrome because of lack of support, but much better in Chrome Canary.

Next step is to integrate PostCSS processors to see if it can fix everything for IE11.

I think I have this working!

I added postcssLogical and postcssDirPseudoClass plugins (see https://git.drupalcode.org/project/olivero/-/commit/654451011d2b9751b823...), and then had to refactor out inset-start and inset-end, which were not supported (see https://git.drupalcode.org/project/olivero/-/commit/4508f47f63cdca000bde...).

I added visual diffs to the tugboat repo to catch any issues (https://git.drupalcode.org/project/olivero/-/commit/ce1ea1e19a164a78e696...), but we'll still need to do plenty of testing in RTL mode!

This is a lot more work than I initially thought. A couple caveats with the postcssLogical plugin.

• It can't handle transform: translatex(x). PostCSS RTL did this automatically.
• It doesn't automatically handle margin shorthand CSS property. This doesn't seem to work with the logical properties, and the margin-block and margin-inline shortcut syntax doesn't seem to work with this.
• It doesn't handle things like box shadows, linear gradients, etc. PostCSS RTL did this automatically.