Populate schema registry on startup

We deploy Debezium with Confluent's Schema Registry. Therefore, the registry serves as our source of truth for all schemas for all messages flowing through our Kafka pipes.

We also heavily use codegen on avro schemas stored in the registry, i.e. in our development environment, we download the latest schemas held in the registry and then generate code from it.

Since we codegen, we need the avro schemas ahead of time. This poses a problem with debezium because schemas are lazy registered with the registry, i.e. the registry doesn't receive the schemas associated with the tables that debezium is connected to until after that table has a new row inserted.

Conceptually, this could be fixed by registering the schemas when debezium starts up.