[8.19](backport #45730) Fix panic in winlog input

[mergify]

Fixes a panic in the winlog input that happened because of a conflict in the internal id of its metrics registry #45693.

When checking whether a registry input id already exists, the check didn't include the ids of input registries with "nested" type (which are unreported containers for cursor-based inputs that can have several sub-inputs inside).

This is usually not a problem because the default (and what most inputs use even when overriding their id, e.g. I think this is why it probably didn't hit the GCP input) is to use a scoped id like "input_id::source_id", so they don't conflict with the container which has bare id "input_id".
This hit winlog in particular because:

• winlog always uses a source id that is the same as its input id
• winlog still used the global input metrics helpers in the inputmon package instead of the metrics registry provided by the Filebeat inputs API
• winlog is the only input that did not add a scope prefix on the id provided to inputmon.NewInputRegistry, so the globally-created registry conflicted with the input manager's container (and this conflict was missed because of the missed "nested" type check above).

Fixing the missed "nested" collision check would prevent the input panic, but the collision itself would still exist and prevent winlog input metrics from being reported.

This PR both fixes the missed "nested" conflict check and removes the deprecated global metrics call from the winlog input, replacing it with the API-provided registry.

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.

Related issues

• Fixes Windows security event processing stops working in versions 9.1.0 and 8.19.0  #45693.

---

This is an automatic backport of pull request #45730 done by [Mergify](https://mergify.com).

[mergify]

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Changes to be committed:
	modified:   CHANGELOG.next.asciidoc
	modified:   filebeat/input/winlog/input.go
	modified:   libbeat/monitoring/inputmon/httphandler.go
	modified:   libbeat/monitoring/inputmon/input_test.go
	modified:   winlogbeat/beater/eventlogger.go
	modified:   winlogbeat/eventlog/eventlog.go
	modified:   winlogbeat/eventlog/runner.go
	modified:   winlogbeat/eventlog/wineventlog_test.go
	modified:   x-pack/winlogbeat/module/testing_windows.go

Unmerged paths:
  (use "git add/rm <file>..." as appropriate to mark resolution)
	deleted by us:   winlogbeat/eventlog/metrics.go
	both modified:   winlogbeat/eventlog/wineventlog.go

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[elasticmachine]

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