Show visual indicator linking localized content items in content list

[sebastienros]

Description

In the Content Items list (/Admin/Contents/ContentItems), localized versions of content appear as separate entries with no visual indication that they are translations of each other.

Current Behavior

1. User creates an English article "Hello World"
2. User creates a French localization "Bonjour le Monde"
3. In the content list, both appear as separate, unrelated items
4. There's no visual indication they are linked localizations

Expected Behavior

Users should be able to quickly identify which content items are localizations of each other.

Suggested Improvements

1. Grouping indicator:

   • Show a "localization group" icon or badge on items that have localizations
   • Hover/click to see linked localizations

2. Inline expansion:

   • Allow expanding a content item row to see its localizations
   • Similar to how child items might be shown in a hierarchical list

3. Culture badges:

   • Show small culture flags or badges (e.g., 🇺🇸 🇫🇷) on items to indicate available localizations

4. Filter/group by localization set:

   • Add a view option to group content items by their localization set
   • Show all localizations of the same content together

5. Link column:

   • Add an optional column showing the localization set ID or linked cultures

Benefits

• Easier content management for multilingual sites
• Quick identification of content needing translation
• Better overview of localization coverage

[github-actions]

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