Add support for Redis Cluster

[charlyx]

Hi 👋

First of all, thanks for your work!

We're trying to use izanami in our project and we'd like to be able to use our redis cluster (AWS ElastiCache) as the database.

Unfortunately, izanami does not work with redis clusters for now. It will need to use another constructor (RedisClusterClient) when in cluster mode.

I was looking at both constructor's code and the only common thing is AbstractRedisClient. I could add a case for the client creation but I don't feel like using AbstractRedisClient in RedisWrapper as a type for underlying would be a nice thing to do.

What do you think?

I'd be quite happy to make a PR though. 😅