Run all user examples in CI

**Is your feature request related to a problem or challenge? Please describe what you are trying to do.**

Per a comment from @mesejo in #880 it would be helpful to run user examples in CI to ensure that our examples stay up to date with any breaking changes in the API.

**Describe the solution you'd like**

Update all user examples if necessary and add code to run them as part of CI.

**Describe alternatives you've considered**

We could leave as is, but this seems like a very good idea.

**Additional context**

This is already being done for TPC-H queries and we can re-use the generated dataset that is already created in CI. Here is where the tests are being run: https://github.com/apache/datafusion-python/blob/main/examples/tpch/_tests.py

Start with examples/tpch/_tests.py and the existing CI configuration that runs TPC-H queries. Identify how the generated dataset is reused, then determine how all user examples can be executed in CI. Done means the examples run successfully in CI and any required updates keep them compatible with the current API.

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