Add all props from dataset, use shared ListLabel model

ee/app/assets/javascripts/epics/epic_show/epic_show_bundle.js

 import Vue from 'vue';
+import '~/vue_shared/models/label';
 import EpicShowApp from './components/epic_show_app.vue';
 
 export default () => {
@@ -6,7 +7,7 @@ export default () => {
   const metaData = JSON.parse(el.dataset.meta);
   const initialData = JSON.parse(el.dataset.initial);
 
-  const props = Object.assign({}, initialData, metaData);
+  const props = Object.assign({}, initialData, metaData, el.dataset);
 
   // Convert backend casing to match frontend style guide
   props.startDate = props.start_date;