Rename methods to add auto links to HTML

The name `safe_html_with_links` was confusing and could make you think
it takes care of making the HTML safe. So I've renamed it in a way that
makes it a bit more intuitive that it expects its input to be already
sanitized.

I've changed `text_with_links` as well so now the two method names
complement each other.

app/views/admin/debates/show.html.erb

@@ -25,7 +25,7 @@
           </span>
   </div>
 
-  <%= safe_html_with_links @debate.description %>
+  <%= auto_link_already_sanitized_html @debate.description %>
 
   <h3><%= t("votes.supports") %></h3>