DEV: Use component references for user menu (#456)

See 9b41700f87 for context.

Passing a reference works before and after that change, so there is no need to introduce a discourse-compatibility entry.

assets/javascripts/discourse/components/user-menu/assigns-list-empty-state.js

@@ -1,3 +0,0 @@
-import templateOnly from "@ember/component/template-only";
-// TODO: colocate this component's template
-export default templateOnly();

assets/javascripts/discourse/components/user-menu/assigns-list.js

@@ -6,6 +6,7 @@ import Notification from "discourse/models/notification";
 import I18n from "I18n";
 import showModal from "discourse/lib/show-modal";
 import Topic from "discourse/models/topic";
+import UserMenuAssignsListEmptyState from "./assigns-list-empty-state";
 
 export default class UserMenuAssignNotificationsList extends UserMenuNotificationsList {
   get dismissTypes() {
@@ -33,7 +34,7 @@ export default class UserMenuAssignNotificationsList extends UserMenuNotificatio
   }
 
   get emptyStateComponent() {
-    return "user-menu/assigns-list-empty-state";
+    return UserMenuAssignsListEmptyState;
   }
 
   async fetchItems() {

assets/javascripts/discourse/initializers/assign-user-menu.js

@@ -1,4 +1,5 @@
 import { withPluginApi } from "discourse/lib/plugin-api";
+import UserMenuAssignNotificationsList from "../components/user-menu/assigns-list";
 
 export default {
   name: "assign-user-menu",
@@ -17,26 +18,15 @@ export default {
         }
         api.registerUserMenuTab((UserMenuTab) => {
           return class extends UserMenuTab {
-            get id() {
-              return "assign-list";
-            }
-
-            get panelComponent() {
-              return "user-menu/assigns-list";
-            }
-
-            get icon() {
-              return "user-plus";
-            }
+            id = "assign-list";
+            panelComponent = UserMenuAssignNotificationsList;
+            icon = "user-plus";
+            notificationTypes = ["assigned"];
 
             get count() {
               return this.getUnreadCountForType("assigned");
             }
 
-            get notificationTypes() {
-              return ["assigned"];
-            }
-
             get linkWhenActive() {
               return `${this.currentUser.path}/activity/assigned`;
             }