TagSetPresenter: refactor to pass options explicitly.

Refactor tag_list_html, split_tag_list_html, and inline_tag_list_html to
take the `show_extra_links` and `current_query` options explicitly,
rather than implicitly relying on CurrentUser or taking `params[:tags]`
from the template.

app/views/posts/index.html.erb

@@ -9,7 +9,7 @@
 
       <section id="tag-box">
         <h1>Tags</h1>
-        <%= @post_set.presenter.tag_list_html(self) %>
+        <%= @post_set.presenter.tag_list_html(current_query: params[:tags], show_extra_links: CurrentUser.user.is_gold?) %>
       </section>
 
       <%= render "posts/partials/index/options" %>