Update to JupyterLite 0.6.0

[jtpio]

Opening an issue to track the update to the next JupyterLite version.

With jupyterlite/jupyterlite#1590, JupyterLite simplifies its code base and the way plugins are being loaded.

For Voici that means:

• Switch from @jupyterlite/server-extension to @jupyterlite/services-extension
• Adopt the same logic in the main entrypoint, by creating a PluginRegistry
• The Service Worker is now provided by @jupyterlite/application-extension:service-worker

jupyterlite/jupyterlite#1590 comes with a detailed list of breaking changes. Will post the link here once the PR is merged into main.

[jtpio]

Migration guide: https://jupyterlite.readthedocs.io/en/latest/migration.html#to-0-6-0