feat(UI): Add expand/collapse functionality for projects with sub-projects.

[nikkuma7]

We want to see the Structure of the projects in the project overview:

We want to see it here:

concern: subprojects can have subprojects -> so the view must be limited to the first level. This feature will be enabled/disabled with the admin configuration key ENABLE_LINKED_PROJECTS_DISPLAY (default: disabled)

Suggest Reviewer

@GMishx and @amritkv

How To Test?

1. Navigate to Admin → Configuration tab
2. Select "Frontend Configuration"
3. Enable "Linked Projects Display in Projects"
   • Default value: false
   • Set to: true
4. Navigate to the Projects tab
5. Link one or multiple projects as sub-projects
6. Verify pagination works correctly for:
   • Main projects
   • Sub-projects
7. Confirm the expand/collapse button is visible on the project overview page
8. Click the expand/collapse button to toggle sub-project visibility
9. Verify expand/collapse buttons appear in:
   • Each project row (for individual projects)
   • Top of the project grid (for all projects)
10. Test disable functionality:
    • Disable "Enable Linked Projects Display" option
    • Confirm sub-project features are hidden

Below SS: