include ksqldb-rocksdb-config-setter in ksqldb-server docker image

[rodesai]

Currently we don't include ksqldb-rocksdb-config-setter in the ksqldb-server docker image. This makes it hard for users to use it to configure ksql with a memory bound. We should fix this and include the config setter by default.

As a workaround, users could copy the jar directly from the s3 maven repo at:
https://ksqldb-maven.s3-us-west-2.amazonaws.com/maven/io/confluent/ksql/ksqldb-rocksdb-config-setter/<ksqldb version>/ksqldb-rocksdb-config-setter-<ksqldb version>.jar

[vcrfxia]

Closing as a dup of #6838