filebeat/module/mysql: add authentication message parsing and related.ip & related.user fields

[leweafan]

What does this PR do?

Adds new patterns, authentication message parsing and related.ip & related.user fields

Why is it important?

Parsing should be ECS compliant and authentication messages parsing important for SIEM

Checklist

• My code follows the style guidelines of this project
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have made corresponding change to the default configuration files
• I have added tests that prove my fix is effective or that my feature works
• I have added an entry in CHANGELOG.next.asciidoc or CHANGELOG-developer.next.asciidoc.

Author's Checklist

• [ ]

How to test this PR locally

Related issues

• Closes Filebeat MySQL slowlog module - user.name exists and related.user field missing #34634
• Closes Filebeat MySQL ingest pipeline can't parse authentication messages for SIEM #32231

Use cases

Screenshots

Logs

[botelastic]

This pull request doesn't have a Team:<team> label.

[mergify]

This pull request does not have a backport label.
If this is a bug or security fix, could you label this PR @leweafan? 🙏.
For such, you'll need to label your PR with:

• The upcoming major version of the Elastic Stack
• The upcoming minor version of the Elastic Stack (if you're not pushing a breaking change)

To fixup this pull request, you need to add the backport labels for the needed
branches, such as:

• backport-v8./d.0 is the label to automatically backport to the 8./d branch. /d is the digit