our CI can't handle it

The newest keycloak library supporst a mode for doing the redirect in an iframe
with a separate page that needs to be whitelisted in keycloak.

The newer version also finally fixes the native promise bugs so we might as well
use the one from npm instead of fetching it from the keycloak server at runtime.

We don't need polyfills in every web component, only once per page.

So we don't install them in the toplevel packages.

Also run tests in gitlab-ci

The main entry point is now src/index.js when included in other packages.