新增：父子关系判断以及可设置为父工作项的列表

app/views/api/pm/issues/parent_issues.json.jbuilder

@@ -0,0 +1,8 @@
+json.total_count @issues.total_count 
+json.issues @issues.each do |issue| 
+  if params[:only_name].present? 
+    json.(issue, :id, :subject, :project_issues_index)
+  else 
+    json.partial! "api/v1/issues/simple_detail", locals: {issue: issue}
+  end
+end