Token based authentication extension libraries

[atakavci]

This PR contains ;

• the Core(redis-authx-core) components for token based authentication as a module to be shared among jedis and lettuce
• A common implementation of authentication(redis-authx-entraid) library to support MS EntraID to help support integration of jedis and lettuce with MS EntraID authentication
• Reqired workflows and configuration regarding to maintain and test both core and entraid modules

Focused aspects are;

• providing possible future extensibility with the core library
• providing generic interfaces/components that allow other identity providers to be implemented.
• keep allowing configurations that MS EntraID support
• providing easy to use and stable interfaces for particular requirements of individual client library(jedis and lettuce) .

[ggivo]

Looks good to me.
I think it is good first version

[tishun]

Aaah a challenging review!

Ali, thanks for all the work, this has been much harder than I personally anticipated.

I generally have few important comments, so none of this is blocking. The main things are:

• we are missing licensing statements, I've added them as suggestions, if you agree you can batch submit them
• we are missing a lot of documentation; I know we can add it later, but I always fear we will never come back to that; my personal minium is documentation for all public API, but in this case I would say please explain a few of the parts in the code that are a bit harder to understand (because of complexity)