Implement support for redis client side caching

[aspark21]

Redis 6 implemented client side caching
https://redis.io/docs/manual/client-side-caching/

I can’t see any mention of phpredis supporting this.

I only found an alternative to phpredis that seemed to offer this https://relay.so/

Can this be added?

I've checked

• There is no similar issue from other users
• Issue isn't fixed in develop branch
• No mention of this in code or docs

[tillkruss]

Relay is actually built by @michael-grunder and @yatsukhnenko and it has the same API as PhpRedis.