Add widget test to searchable listview

[koukibadr]

Use case

Currently, the searchable ListView component lacks widget test coverage. We should add comprehensive widget tests to ensure the search functionality and list rendering work correctly.
Acceptance Criteria

• Test initial list rendering
• Test search input updates filter results
• Test empty search results state
• Test clearing search resets list
• Test async listview
• Test silver listview component
• Test expandable listview

Proposal

No response