Implement the new account settings screen

Under the new nav, we're creating a new two column layout for the settings screen

https://design.minds.com/hosted/web/michael/front%232153-settings/#artboard0

• Left hand panel with the settings nav
• Right hand panel with the individual settings screens
• Light mode
• Dark mode
• Unit tests
• End to end tests
• Behind a "settings" feature flag that must be mapped on the backend in the feature flags service