restore CE version of route to reduce possibility for conflicts

app/assets/javascripts/pages/projects/merge_conflicts/index.js

+import initSidebarBundle from '~/sidebar/sidebar_bundle';
+import initMergeConflicts from '~/merge_conflicts/merge_conflicts_bundle';
+
+document.addEventListener('DOMContentLoaded', () => {
+  initSidebarBundle();
+  initMergeConflicts();
+});