Implement the new user settings / dropdown

When the user clicks on their channel avatar, display the new old settings page with the new look

New gitlab home for the settings dropdown

Dark mode for settings https://design.minds.com/hosted/web/michael/front%232148-navigation/#artboard11

Light mode for settings https://design.minds.com/hosted/web/michael/front%232148-navigation/#artboard23

• Move the channel avatar to the right hand side
• Remove the hamburger menu
• Clicking the channel avatar should open the old settings menu
• Use the old settings menu, but update the look
• Move the footer links to the bottom of the settings menu
• Make the more link take them to the "/p" static content index page
• responsive design
• light mode
• dark mode
• unit tests
• e2e tests