♻️(front) update web-streams-polyfill import

The package web-streams-polyfill has released a new major version and
the export are not the same anymore. We have to upgrade the one we use
to be comptible with version 4.
https://github.com/MattiasBuelens/web-streams-polyfill/blob/master/MIGRATING.md

src/frontend/packages/lib_components/testSetup.js

@@ -1,5 +1,5 @@
 import 'marsha-config/jest/testSetup';
-import { TransformStream } from 'web-streams-polyfill/ponyfill';
+import { TransformStream } from 'web-streams-polyfill/es5';
 
 const tds = {
  start() {