fix(list-details): prevent half visible content

[spike-rabbit]

The previous overflow:hidden approach was not sufficient in certain cases (exact reason is unknown).
Using contain: layout is anyway better
since it decouples the internal layout.

Please check in Safari. There used to be a problem when using transform (which should be preferred over margin as it can be hardware accelerated)

Describe in detail what your merge request does and why. Add relevant
screenshots and reference related issues via Closes #XY or Related to #XY.

---

• I confirm that this MR follows the contribution guidelines.

[gemini-code-assist]

Summary of Changes

Hello @spike-rabbit, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request addresses an issue where content within the list details component could appear partially visible by updating its CSS styling. It transitions from an overflow-x: hidden approach to contain: layout for better rendering isolation and refactors the component's animation to leverage CSS transform properties, resulting in more efficient and visually consistent transitions.

Highlights

• CSS Property Update: Replaced the overflow-x: hidden property with contain: layout in the main container of the list details component. This change aims to prevent content from being half visible and improves layout isolation, enhancing rendering performance and predictability.
• Animation Refactor: The animation for the .list-details element has been refactored to use transform: translateX instead of margin-inline-start. This provides a smoother and more performant transition when the details panel is activated, as transform changes typically avoid triggering layout recalculations.

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[gemini-code-assist]

Code Review

This pull request refactors the CSS for the si-list-details component to address a content visibility issue. The changes involve replacing overflow-x: hidden with contain: layout for better layout containment and switching from margin-based animations to transform-based animations for improved performance. While these are positive changes, the switch to transform: translateX introduces a regression for right-to-left (RTL) language support, as it's a physical property that doesn't adapt to text direction. My review highlights this issue and provides recommendations for a fix.

[github-actions]

Documentation.
Examples.
Playwright report.

Coverage Reports:

• element-ng
• element-translate-ng

[github-actions]