feat(medusa): Allow to pass custom options to the ioredis instance

[adrien2p]

At the moment, the only available config for redis is the redis_url

The problem is that if as a consumer you need to customise your redis instance options it is not possible.

Example, on heroku I set a redis tls instance with a self signed certificate. I must set the following options to redis

{
    tls: {
        rejectUnauthorized: false
    }
}

Which is required but not possible at the moment.

This PR allow the consumer to configure his redis instance.

[adrien2p]

@olivermrbl any thoughts about that?

[adrien2p]

@olivermrbl ive seen that we have both redis/ioredis, any reason in particular to use both?