Kafkacrypto

This release corrects one typo in the forward-compatibility logic and description for librdkafka in confluent_kafka_wrapper.

This is a bufix release with a single change to ensure forward compatibility with the upcoming libkrdkafka 1.9.0:

- Update confluent_kafka_wrapper to properly handle errors due to commits with no offset in the synchronous case.

This ensures compatibility with a bugfix entailing behavior change in librdkafka regarding the behavior of commit calls with topics that are subscribed but not yet assigned.

This is a bufix release. Changes:

- Scope custom flush work-around in confluent_kafka wrapper to only affected versions. See [librdkafka3633](https://github.com/edenhill/librdkafka/issues/3633).
- Make confluent_kafka consumer commit wrapper synchronous to match kafka-python API expectations.
- Add commit_async handler to confluent_kafka wrapper.
- Fix missing lock acquire in __update_spk_chain.

This release adds the ability to close KafkaCrypto/KafkaCryptoStore, and bumps version for consistency with the python implementation.

This release improves direct key exchange logic, and bumps version for consistency with the python implementation.