fix: Do not rely on class names in production bundle (#6212)

app/models/CollectionGroupMembership.ts

@@ -1,14 +1,25 @@
 import { observable } from "mobx";
 import { CollectionPermission } from "@shared/types";
+import Collection from "./Collection";
+import Group from "./Group";
 import Model from "./base/Model";
+import Relation from "./decorators/Relation";
 
 class CollectionGroupMembership extends Model {
+  static modelName = "CollectionGroupMembership";
+
   id: string;
 
   groupId: string;
 
+  @Relation(() => Group, { onDelete: "cascade" })
+  group: Group;
+
   collectionId: string;
 
+  @Relation(() => Collection, { onDelete: "cascade" })
+  collection: Collection;
+
   @observable
   permission: CollectionPermission;
 }