Python: setup samples as integration tests

[eavanvalkenburg]

Python version of Semantic Kernel has a setup to verify samples as integration tests:
https://github.com/microsoft/semantic-kernel/tree/main/python/tests/samples

We need to create the same setup in Agent Framework.

[markwallace-microsoft]

@giles17 Just to be clear, we don't want to change the structure of the samples but we do want to create integration tests which invoke the samples and confirm they are working as expected.