Update Unwrap/UnwrapMongoDB SMT demos to use latest Debezium and delete event support

Both unwrap-smt and unwrap-mongodb-smt use older versions of the PostgreSQL driver, Kafka Connect JDBC sink, and Debezium. The examples should be upgraded to Debezium 0.10, PostgreSQL driver 42.2.8, and Kafka Connect JDBC 5.3.1. The example should also be updated to include the new JDBC sink delete support.