Topbar fixes

Stumbled across ticket #4513 where someone was complaining about not wanting to use a `<section>` inside top bar. It was an easy enough fix that is probably for the best as it now looks for `top-bar-section` class instead of just a `section` element

This also fixes an annoying issue when Top Bar is sticky. When not all of the content on the page has loaded, some times Top Bar and jump to the fixed position too soon.