Update to jlab 3.0a11

[jasongrout]

No description provided.

[blink1073]

Need to update local copy of webpack for compatibility based on traceback

[jasongrout]

I think we've ported all the interesting logic here over to the jlab examples module, and that example also includes more interesting things (like an extension having multiple plugins). Should we keep this repo at this point?

[blink1073]

We haven't yet proven out an extension chain, correct?

[jasongrout]

Yes, we have with the last alpha, IIRC.

[jasongrout]

I noticed the built-in example does not have an example of an extension chain, so I'm adding that.

However I'm also noticing the built-in example is broken, and showing places where master is broken, once you copy the built-in federated example out of the main source tree and try building it independently.

[jasongrout]

However I'm also noticing the built-in example is broken, and showing places where master is broken, once you copy the built-in federated example out of the main source tree and try building it independently.

So first I'm fixing that :). See also jupyterlab/jupyterlab#8844