Add settings_checkout_tabs sub section partial

This partial will be related for settings related to actions related to
checking out including refund reasons, reimbursement types, return
reasons, and adjustment reasons.

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

@@ -0,0 +1,21 @@
+<% content_for :tabs do %>
+ <nav>
+ <ul class="tabs" data-hook="admin_settings_checkout_tabs">
+ <% if can?(:display, Spree::RefundReason) %>
+ <%= settings_tab_item Spree::RefundReason.model_name.human(count: :other), admin_refund_reasons_path %>
+ <% end %>
+
+ <% if can?(:display, Spree::ReimbursementType) %>
+ <%= settings_tab_item Spree::ReimbursementType.model_name.human(count: :other), admin_reimbursement_types_path %>
+ <% end %>
+
+ <% if can?(:display, Spree::ReturnReason) %>
+ <%= settings_tab_item Spree::ReturnReason.model_name.human(count: :other), admin_return_reasons_path %>
+ <% end %>
+
+ <% if can?(:display, Spree::AdjustmentReason) %>
+ <%= settings_tab_item Spree::AdjustmentReason.model_name.human(count: :other), admin_adjustment_reasons_path %>
+ <% end %>
+ </ul>
+ </nav>
+<% end %>