Add settings sub section store partial

This partial will be displayed on the tracker, taxonomy, and general
settings pages.

backend/app/views/spree/admin/shared/_store_tabs.html.erb

@@ -0,0 +1,17 @@
+<% content_for :tabs do %>
+ <nav>
+ <ul class="tabs" data-hook="admin_settings_store_tabs">
+ <% if can?(:edit, :general_settings) %>
+ <%= settings_tab_item Spree.t(:general_settings), edit_admin_general_settings_path %>
+ <% end %>
+
+ <% if can?(:display, Spree::Tracker) %>
+ <%= settings_tab_item Spree.t(:analytics_trackers), admin_trackers_path %>
+ <% end %>
+
+ <% if can?(:display, Spree::Taxonomy) %>
+ <%= settings_tab_item Spree::Taxonomy.model_name.human(count: :other), admin_taxonomies_path %>
+ <% end %>
+ </ul>
+ </nav>
+<% end %>