Rollup merge of #103211 - notriddle:notriddle/dot-location, r=GuillaumeGomez

rustdoc: remove class name `location` from sidebar sibling nav

Preview: https://notriddle.com/notriddle-rustdoc-demos/sidebar-location/std/vec/struct.Vec.html

This change tweaks the CSS to apply most of its styles to `.sidebar h2`, cleaning up a few redundant rules from `.mobile-topbar .location` and restoring useful navigation aids in mobile mode.

## Before

![location-before](https://user-images.githubusercontent.com/1593513/196521014-d8730830-c3a2-4ed7-9266-05454cd31e05.png)

## After

![location-after](https://user-images.githubusercontent.com/1593513/196521020-75ec1fa5-b3dc-4c5d-97b6-afccb5fbe00a.png)

src/librustdoc/html/render/mod.rs

@@ -1884,7 +1884,7 @@ fn print_sidebar(cx: &Context<'_>, it: &clean::Item, buffer: &mut Buffer) {
     if !it.is_mod() {
         let path: String = cx.current.iter().map(|s| s.as_str()).intersperse("::").collect();
 
-        write!(buffer, "<h2 class=\"location\"><a href=\"index.html\">In {}</a></h2>", path);
+        write!(buffer, "<h2><a href=\"index.html\">In {}</a></h2>", path);
     }
 
     // Closes sidebar-elems div.