Move EE differences for `app/assets/javascripts/filtered_search/filtered_search_manager.js `

The file app/assets/javascripts/filtered_search/filtered_search_manager.js has differences between CE and EE.

Diferences

diff --git a/home/yorickpeterse/Projects/gitlab/gdk-ce/gitlab/app/assets/javascripts/filtered_search/filtered_search_manager.js b/home/yorickpeterse/Projects/gitlab/gdk-ee/gitlab/app/assets/javascripts/filtered_search/filtered_search_manager.js
index 33c82778c79..a54b88b78df 100644
--- a/home/yorickpeterse/Projects/gitlab/gdk-ce/gitlab/app/assets/javascripts/filtered_search/filtered_search_manager.js
+++ b/home/yorickpeterse/Projects/gitlab/gdk-ee/gitlab/app/assets/javascripts/filtered_search/filtered_search_manager.js
@@ -41,6 +41,9 @@ export default class FilteredSearchManager {
       merge_requests: 'merge-request-recent-searches',
     };
 
+    // EE specific setup
+    this.initEE();
+
     this.recentSearchesStore = new RecentSearchesStore({
       isLocalStorageAvailable: RecentSearchesService.isAvailable(),
       allowedKeys: this.filteredSearchTokenKeys.getKeys(),
@@ -55,6 +58,26 @@ export default class FilteredSearchManager {
     this.recentSearchesService = new RecentSearchesService(recentSearchesKey);
   }
 
+  /**
+   * Do EE specific initializations
+   */
+  initEE() {
+    // Setup token keys for multiple-assignees support
+    if (typeof this.filteredSearchTokenKeys.init === 'function') {
+      this.filteredSearchTokenKeys.init({
+        multipleAssignees: this.filteredSearchInput.dataset.multipleAssignees,
+      });
+    }
+
+    // Add localStorage key name for Epics recent searches
+    this.recentsStorageKeyNames.epics = 'epics-recent-searches';
+
+    // Update `isGroup` from DOM info
+    if (this.filteredSearchInput) {
+      this.isGroup = !!this.filteredSearchInput.getAttribute('data-group-id');
+    }
+  }
+
   setup() {
     // Fetch recent searches from localStorage
     this.fetchingRecentSearchesPromise = this.recentSearchesService

https://leipert-projects.gitlab.io/is-gitlab-pretty-yet/diff/?search=filtered_search_manager.js

What needs to be done

1. Create a EE counterpart in the ee/ folder.
2. Extend the FilteredSearchManager class.
3. Move the differences to the ee counterpart
4. In the places the file is being imported, use ee_else_ce to import it
5. Guarantee that specs exist or are added