feat: added async & persistent options to Cache Redis

[ddevsr]

Description
Added config item to Redis in Cache.

Parameter:

• Added async and persistent config item to predis handler.
• Added persistent config item to redis handler.

Checklist:

• Securely signed commits
• Component(s) with PHPDoc blocks, only if necessary or adds value (without duplication)
• Unit testing, with >80% coverage
• User guide updated
• Conforms to style guide

[neznaika0]

No tests required?

Change config in https://github.com/codeigniter4/CodeIgniter4/blob/4.7/user_guide_src/source/libraries/caching.rst#redis-caching

[michalsn]

PHPRedis can also support the persistent option, so we should add it there too via pconnect().

The async option should note that it is used only with Predis.

Preferably, all these new options should be mentioned here: https://codeigniter.com/user_guide/libraries/caching.html#redis-caching

---

We could introduce a separate configuration parameter for Predis in the config and switch to using new Redis() in the PHPRedis implementation. This would allow us to support all available options in both clients without worrying about missing or incompatible parameters. However, this change would introduce a minor BC break. Thoughts?

[ddevsr]

Added for redis handler too. I want make support Sentinel, but for next PR. Maybe separate config in that PR

[neznaika0]

I don't use Redis, but it looks good.

[ddevsr]

PR #9793 for Session

[michalsn]

Some documentation updates.

[michalsn]

Looks good, thanks!

PHPStan errors are not related.

[michalsn]

@ddevsr The 4.7 branch has been updated - PHPStan errors should go away. Please rebase when you have time.

[michalsn]

Thank you @ddevsr!