Implement new notification dropdown

Reskin the existing notification drop down into the new designs

Overview

https://design.minds.com/hosted/web/michael/front%232148-navigation/#artboard0

Notification dropdown mockup

https://design.minds.com/hosted/web/michael/front%232148-navigation/#artboard3

Light mode

https://design.minds.com/hosted/web/michael/front%232148-navigation/#artboard15

• Update and move the notification icon to the right hand side.
• Reskin the dropdown
• Shrink the height and display fewer notifications by default
• Change the "View all" text to "See all notifications
• Responsive
• Light mode
• Dark mode
• Unit tests
• e2e tests