outline panel: Improve the search query header design (#25283)

Fine-tuning alignment and spacing.

| Before | After |
|--------|--------|
| ![CleanShot 2025-02-20 at 5  45
09@2x](https://github.com/user-attachments/assets/0db377b2-e030-4a88-8465-fb8c3a535ad3)
| ![CleanShot 2025-02-20 at 5  44
33@2x](https://github.com/user-attachments/assets/ccabef92-3e2b-47b8-a766-2f707d9d9e8f)
|

Release Notes:

- N/A