docs(logging): log4j2 support updates

[PaulRMellor]

Documentation

Updates the logging content to reflect new support and Kafka 4.0 adoption of log4j2

• Removes/updates references to log4j1 and log4j1 logger names
• Updates logging content in the deploying guide
  • Refreshes logging config overview
• streamlines logging information in API reference guide to remove repetition

Checklist

Please go through this checklist and make sure all applicable tasks have been done

• Write tests
• Make sure all tests pass
• Update documentation
• Check RBAC rights for Kubernetes / OpenShift roles
• Try your changes from Pod inside your Kubernetes and OpenShift cluster, not just locally
• Reference relevant issue(s) and close them after merging
• Update CHANGELOG.md
• Supply screenshots for visual changes, such as Grafana dashboards

[PaulRMellor]

Thanks for the comments @fvaleri
I've updated the examples as directed.
I've also updated the section on adding logging filters (appenders) based on your feedback.

[fvaleri]

LGTM. Thanks.

[PaulRMellor]

Thanks @scholzj
I've returned to the logger sectiond in the API guide and made the preconfigured logger lists consistent with the change suggested for the bridge.
I've split the examples so the custom loggers are separate.

[scholzj]

Sorry, being away from work, I do not have really enough time to focus on the PR all at once. So there is always a bunch of new things I notice with every pass. I imagine it must be hard to keep changing things again and again. Sorry :-(.

[PaulRMellor]

Thanks for considering how to make the content clearer @scholzj
I've separated the inline and external examples, moving the descriptions to introduce each separately

[scholzj]

Few more nits, but LGTM otherwise. I already approved it.

[ppatierno]

LGTM. Just a nit from me (and of course agree with the ones raised by Jakub)