Add support for ACL commands

[atakavci]

This brings the support for REDIS ACL (short for Access Control List) set of commands which are long time existing on Redis (available since 6.0.0).
The list of commands included in the PR;

• ACL CAT
• ACL DELUSER
• ACL GENPASS
• ACL GETUSER
• ACL LIST
• ACL LOAD
• ACL LOG
• ACL SAVE
• ACL SETUSER
• ACL USERS
• ACL WHOAMI

More details and doc;
👉 https://redis.io/docs/latest/commands/acl/
👉 https://redis.io/docs/latest/operate/oss_and_stack/management/security/acl/

[atakavci]

hi @mgravell , @NickCraver
i believe this brings some good level of support for ACL commands. Only ACL DRYRUN is missing in the PR, and i plan to leave it since it has very limited use case.
please let me know what you think..

[mgravell]

We discussed and reviewed this in our regular meetings; after much discussion, we reached some thoughts:

• this is a large PR, that contributes a large API surface into the core, for a relatively niche admin operation (rather than routine runtime)
• the API surface may need to evolve over time, which is very difficult in the core
• we think this would work better as a bolt-on additional package, rather than expanding the core (name TBD)
• we also think this might serve as an ideal test-case for the upcoming new modules / custom commands API, rather than forcing everything to use blind Execute

Proposal: when the pre-reqs are in place, @mgravell to work with @atakavci to rework this (much appreciated) effort into that shape; this could sit as a Redis Ltd owned package, or we could absorb it into a satellite package here, with looser versioning rules than the core - TBD.

Thoughts?