notifications: update featured notification icon

[kabeaty]

What does this PR do?

Updates the icon for notifications for featured comments.

These changes will impact:

• [x] commenters
• [ ] moderators
• [ ] admins
• [ ] developers

What changes to the GraphQL/Database Schema does this PR introduce?

none

Does this PR introduce any new environment variables or feature flags?

no

If any indexes were added, were they added to INDEXES.md?

n/a

How do I test this PR?

You can feature a comment and then log in as the commenter whose comment was featured to see the notification for it. You should see the rating star ribbon icon beside this notification.

Were any tests migrated to React Testing Library?

How do we deploy this PR?