Add tests against real brokers (testcontainers-python)

[tribunsky-kir]

The current testcontainers-kafka is nice but has very limited functionality (no ZooKeeper or Schema Registry out of the box).

In fact, wunderkafka is not automatically tested against real brokers, which requires additional effort to test it manually (via docker compose locally or against running cluster).

[tofuurem]

How exactly do you see this issue being resolved?
Do a heavy stack of integration testing?

[yv-svstl]

I would look into faststream tests. They don't have zookeper and sr, but the implementation would be similar i guess