roachtest: use prebuilt image for CDC roachtests

Consider the `cdc/tpcc-100/10min/sink=kafka/*` tests, which spin up a kafka cluster as well as a local prometheus instance. This setup takes roughly ~5 minutes out of the ~13 minutes overall it took the test to complete. This pattern is common throughout many CDC roachtests and we could cut down significantly on test time if we didn't have to set this up every time.

It would be nice if we had a way to easily pre build images with kafka + prom installed, e.g. using https://github.com/hashicorp/packer and spin up roachtests from that instead. https://github.com/cockroachdb/cockroach/issues/147352 describes a similar solution which would also be acceptable.

For CDC specifically, we want to test multiple versions of kafka. At the bare minimum we want to the the oldest and new supported versions, but even better if we can find a way to easily test more. One proposed way to do this without creating an image per version would be to just stick both versions in the same image under different binaries.

Jira issue: CRDB-62947