Expose option to enable error_on_callbacks in KafkaProducer.send

[aiven-anton]

With Future.error_on_callbacks == False, the default, errors raised in callbacks are suppressed (even critical ones like MemoryError). The only feasible way to change this behavior is currently to override the class attribute, but this has global effects and might not be possible in a large application with multiple usages and different needs. I'm proposing to change this class attribute to an instance attribute, and expose a way to change its value, either through instantiation of KafkaProducer, or by passing a parameter to .send().