…ient types

The `READONLY` command is sent to replicas as a setup command before
the connection is handed to the caller. This command should only be
sent to replicas in the cluster mode (see [1]). The sentinel mode
didn't use it, but the replication mode did, which is a bug and
causes all replicas to be ignored (because the setup command fails).
This commit fixes it.

[1] https://redis.io/commands/readonly/

- update Testcontainers
- add logging configuration, more readable than JUL default

For each Redis deployment style (standalone, replication, sentinel, cluster),
there's a class that can be used as a JUnit test rule and internally uses
Testcontainers to run Redis. They provide some basic startup guarantees,
so users don't need to wait for a server to come online etc.

The helper class for standalone Redis allows customizing the Redis version,
setting a password, and enabling TLS (including mutual TLS). The multi-node
variants assume basic configuration and don't allow customization.

These helper classes use the Bitnami images, because they provide environment
variables for all the necessary customizations. The multi-node variants also
use Docker Compose.

The improvements mostly consist of using the new Redis helper classes
for running standalone/replication/sentinel/cluster Redis, instead
of the previous approach with a single container for multi-node
deployments, which is not realistic and can hide bugs, but there are
other improvements too. Notably, the TLS test uses actual Redis TLS
support instead of a Vert.x-based TLS proxy, and the multi-node tests
verify that data replication actually works. Some useless tests are
deleted, too.