[#6441] Hide and disable unassignable deliverables from the issue

* Hide - Closed deliverables
* Hide - Closed contract deliverables
* Disable - Locked deliverables
* Disable - Locked contract deliverables

app/views/issues/_edit_deliverable.html.erb

@@ -1,6 +1,6 @@
 <% if project.module_enabled?(:contracts) && User.current.allowed_to?(:assign_deliverable_to_issue, project) %>
   <p>
-    <%= form.select(:deliverable_id, grouped_options_for_select(deliverable_options(project), issue.deliverable_id), {:include_blank => true}) %>
+    <%= form.select(:deliverable_id, grouped_deliverable_options_for_select(project, issue.deliverable_id), {:include_blank => true}) %>
   </p>
 <% end %>