Update to ServiceX client v3.0.x API

[matthewfeickert]

Cross listing of ssl-hep/ServiceX_frontend#493:

The existing ServiceX client docs for FuncADL Query Type give this Jupyter Book as the full user docs reference.

Full documentation on the func-adl query language can be found at this `JupyterBook <https://gordonwatts.github.io/xaod_usage/intro.html>`_. 

However, that Jupyter Book isn't using the v3.0.x API (very understandably!), so this will be important to update, in addition to PR #20.

This is work that shouldn't be the responsibility of @gordonwatts though, and will require contributions from other ATLAS members and ServiceX development team members.