Notification Settings adjustments

[nqst]

Changes:

• Updated the title to use the singular form and capitalization (Notification Settings instead of Notifications settings).
• Set the same top margin for the Notification Settings panel group as in Account Settings.
• Normalized the corner radius in .notification__status so it looks more balanced with the parent .panel, especially on mobile.
• Changed the Chrome label to Google Chrome in the "Help me fix this" instructions for macOS. This matches how it appears in System Settings and may save time when searching the list.
• Added a missing comma.

Preview

Before	After

P.S. Merry Christmas everyone! 🎄