deadpool-redis: Allow setting timeouts

[loewenheim]

Currently deadpool_redis::Manager and deadpool_redis::cluster::Manager don't support Redis timeouts (e.g. a response timeout). Our workaround in getsentry/relay#5329 is to basically reimplement those structs with timeouts included.

For cluster::Manager, this could be accomplished by providing a constructor function that accepts a pre-configured ClusterClient. Unfortunately that doesn't work for the non-cluster case because there timeouts can't be configured on the Client. Another solution that covers both use cases could be to allow storing a configuration on the Manager and pass it to the client on every connection creation.