Instead of fetching it from the configured keycloak server.

We had this initially, but switched to the server variant to make
sure we are always compatible with the keycloak version.

Now upstream keycloak has deprecated this strategy and in Keycloak 22
the server provided js bundle will be removed.

So switch back to the npm package.

The old version is no longer maintained and doesn't support rollup v3

It has new API which we want to use.

Newest Ubuntu switched Firefox to a snap, which breaks karma.

Try to use playwright to download and cache firefox/chromium
and use those for karma.

Compared to puppeteer where we did this some time ago this caches
the browsers globally, and only downloads them when we start the tests.

This reverts commit 6324718b.

This reverts commit 3716524b.

Just change all imports and dependencies.

No longer needs babel, but requries an alpha version of the typescript plugin
for eslint 8 support