Tests for Brokers

[alexiudice]

Feature description

Add tests for the broker package. Tests should include broker configuration, connecting, sending/receiving messages, message configuration, procedures, and error handling.

I'm thinking this could be done with the test containers integration already present in apoc.

How this feature can improve the project?

Consistency of broker features and across branches. Acts as a sanity-check so newly merged in features will not break existing features.