[sink jdbc-clickhouse] avro (and possibly others) sink is broken

**Describe the bug**

When publishing & consuming messages avro & json schema encoding works as expected. After creating a simple clickhouse sink (using config from the docs), the messages get written to the table, but every value is `null`, making it useless. Downgrading to 2.7.2 re-running the test it all works as expected. No avro, db schema changes or sink config changes are needed when downgrading.

**To Reproduce**
Steps to reproduce the behavior:
1. Start up a clickhouse and pulsar-standalone
1. Create a clickhouse sink attached to the test topic
2. Publish some messages with avro schema (i used go client for this)
4. See error

**Expected behavior**

I expect the sink to correctly populate my fields.

Start by reproducing the issue with ClickHouse, a Pulsar standalone instance, the JDBC sink, and Avro messages as described. Compare the current behavior with version 2.7.2; done means the sink populates the ClickHouse table fields instead of writing null values.

Written by the indexing model from the issue text.