create id in mock data

src/Umbraco.Web.UI.Client/src/mocks/data/entity.data.ts

@@ -1,4 +1,5 @@
 import { UmbData } from './data.js';
+import { UmbId } from '@umbraco-cms/backoffice/id';
 import type { UmbEntityBase } from '@umbraco-cms/backoffice/models';
 
 // Temp mocked database
@@ -23,6 +24,12 @@ export class UmbEntityData<T extends UmbEntityBase> extends UmbData<T> {
 	}
 
 	insert(item: T) {
+
+		// TODO: Remove this fix when all types come with an ID them selfs.
+		if (!item.id) {
+			item.id = UmbId.new();
+		}
+
 		const exits = this.data.find((i) => i.id === item.id);
 
 		if (exits) {
@@ -30,6 +37,8 @@ export class UmbEntityData<T extends UmbEntityBase> extends UmbData<T> {
 		}
 
 		this.data.push(item);
+
+		return '/header/location/id/'+item.id;
 	}
 
 	save(saveItem: T) {