Wait for design tab to be active

The design management test tries to change the style of an element on
the design tab immediately after clicking the link to switch to the
tab. This change waits for the tab to become active after clicking it.

ee/app/views/projects/issues/_discussion.html.haml

@@ -5,13 +5,13 @@
         = _('Discussion')
         %span.badge.badge-pill.js-discussions-count
     %li
-      = link_to '#designs-tab', class: 'js-issue-tabs', id: 'designs', role: 'tab', 'aria-controls': 'js-designs', 'aria-selected': 'false', data: { toggle: 'tab', target: '#designs-tab', qa_selector: 'designs_tab' } do
+      = link_to '#designs-tab', class: 'js-issue-tabs', id: 'designs', role: 'tab', 'aria-controls': 'js-designs', 'aria-selected': 'false', data: { toggle: 'tab', target: '#designs-tab', qa_selector: 'designs_tab_link' } do
         = _('Designs')
         %span.badge.badge-pill.js-designs-count
   .tab-content
     #discussion-tab.tab-pane.show.active{ role: 'tabpanel', 'aria-labelledby': 'discussion' }
       = render_ce 'projects/issues/discussion'
-    #designs-tab.tab-pane{ role: 'tabpanel', 'aria-labelledby': 'designs' }
+    #designs-tab.tab-pane{ role: 'tabpanel', 'aria-labelledby': 'designs', data: { qa_selector: 'designs_tab_content'} }
       #js-design-management{ data: { project_path: @project.full_path, issue_iid: @issue.iid, issue_path: project_issue_path(@project, @issue) } }
 - else
   = render_ce 'projects/issues/discussion'

qa/qa/ee/page/project/issue/show.rb

@@ -33,13 +33,15 @@ module QA
                 end
 
                 view 'ee/app/views/projects/issues/_discussion.html.haml' do
-                  element :designs_tab
+                  element :designs_tab_link
+                  element :designs_tab_content
                 end
               end
             end
 
             def click_designs_tab
-              click_element(:designs_tab)
+              click_element(:designs_tab_link)
+              active_element?(:designs_tab_content)
             end
 
             def click_remove_weight_link