Render components instead of partials in headers

We were using partials to render components in order to ease the
transition of custom code from earlier versions of Consul. However,
that was back in Consul 1.4, and now these views looked a bit messy
since they sometimes rendered components and sometimes they
rendered partials.

app/views/layouts/_header.html.erb

@@ -4,9 +4,9 @@
   <% end %>
 
   <div class="top-links">
-    <%= render "shared/locale_switcher" %>
+    <%= render Layout::LocaleSwitcherComponent.new %>
     <div class="hide-for-small-only">
-      <%= render "shared/top_links" %>
+      <%= render Layout::TopLinksComponent.new %>
     </div>
   </div>
 
@@ -23,7 +23,7 @@
       <div class="show-for-small-only">
         <div class="subnavigation subnavigation-with-top-links">
           <%= render Layout::SubnavigationComponent.new %>
-          <%= render "shared/top_links" %>
+          <%= render Layout::TopLinksComponent.new %>
         </div>
       </div>
     <% end %>