Top navigation redesign

What does this MR do?

Start of the new navigation redesign by redesigning just the top navigation bar. This is only visible when a cookie is set.

A section to /profile/preferences has been added to allow the user to turn on & off this feature.

Screenshots (if relevant)

What are the relevant issue numbers?

#32794 (closed)

Closes #34022 (closed), #34035 (closed), #34037 (closed), #34038 (closed), #34021 (closed)