making the top_navigation_bar its own nested liveview

[wintermeyer]

Let’s do this:
Note that due to liveview's double remounting the queries fetching for random interests are executed twice. We can improve this by making the top_navigation_bar its own nested liveview, which would save the number of sql queries executed even on navigation to other routes.

[briankariuki]

We may still have double remounting in the nested liveview (unless we use liveview's async_assigns), but since we can make it sticky, we'll save some sql queries on page navigations