Update search bar component

[ginny-d]

🔗 Figma link to component

• Related (empty state): https://github.com/hirosystems/explorer/issues/1485
• Related: https://github.com/hirosystems/explorer/issues/1493
• Related: https://github.com/hirosystems/explorer/issues/1494

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• Align search dropdown to search input field
• Remove "search results/not found" title (redundant)
• Update error/empty state