⬆️ Upgrade to MSW 2.x

Major version bump, so the mocks had to be updated too. This should
make upgrading Storybook easier in the future since we don't need to
pin MSW to 1.x

.storybook/preview.js

@@ -1,7 +1,7 @@
 import '../src/openforms/scss/screen.scss';
 import '../src/openforms/scss/admin/admin_overrides.scss';
 import {withModalDecorator, withReactSelectDecorator} from 'components/admin/form_design/story-decorators';
-import {initialize, mswDecorator, mswLoader} from 'msw-storybook-addon';
+import {initialize, mswLoader} from 'msw-storybook-addon';
 import {reactIntl} from './reactIntl.js';
 import ReactModal from 'react-modal';
 
@@ -15,7 +15,7 @@ initialize({
 ReactModal.setAppElement(document.getElementById('storybook-root'));
 
 export default {
-  decorators: [mswDecorator, withModalDecorator, withReactSelectDecorator],
+  decorators: [withModalDecorator, withReactSelectDecorator],
   parameters: {
     controls: {
       matchers: {