Summary
Fixes PropType validation warnings that were causing test failures and updates test factories to include all required data fields.

Changes Made

1. PropType Validation Fixes NotificationRowItem Component
2. Migrated from deprecated defaultProps to JavaScript default parameters. Changed and lastRead from required to optional PropTypes
3. Added default values: type = '' , lastRead = '' in Notifications Component

Notifications Component

1. Made notificationExpiryDays optional in PropTypes to handle undefined values gracefully
2. Added nullish coalescing operator (??) to ensure notificationExpiryDays always defaults to 0

Test Data Updates Notification Factory (notifications.factory.js)

1. Added notification_expiry_days: 60 to notificationsCount factory
2. Ensures all test mocks provide complete data matching API contracts