[9.1](backport #48075) Remove direct access to v2.Context.StatusReporter in Filestream

[mergify]

Proposed commit message

v2.Context.StatusReporter can be nil when Filebeat runs standalone. The direct access to this field is replaced in Filestream by the UpdateStatus method. A deprecation notice is added is added to the StatusReporter field.

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. Where relevant, I have used the stresstest.sh script to run them under stress conditions and race detector to verify their stability.
• I have added an entry in ./changelog/fragments using the changelog tool.

## Disruptive User Impact
## Author's Checklist

How to test this PR locally

1. Create a log file

docker run -it --rm mingrammer/flog -n 50 > /tmp/flog.ndjson

2. Run Filebeat with the following configuration

filebeat.yml

filebeat.inputs:
  - type: filestream
    id: filestream-input-id
    paths:
      - /tmp/flog.log
    processors:
      - add_fields:
          INVALID_CONFIG_KEY: true
          fields:
            labels:
              foo: bar

logging:
  to_stderr: true

output.discard:
  enabled: true

It should not panic

## Related issues
## Use cases
## Screenshots
## Logs

---

This is an automatic backport of pull request #48075 done by [Mergify](https://mergify.com).

[mergify]

Cherry-pick of 72314a0 has failed:

On branch mergify/bp/9.1/pr-48075
Your branch is up to date with 'origin/9.1'.

You are currently cherry-picking commit 72314a046.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Changes to be committed:
	modified:   filebeat/input/v2/input.go

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   filebeat/input/filestream/internal/input-logfile/harvester.go

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally

[github-actions]

🤖 GitHub comments

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[elasticmachine]

Pinging @elastic/elastic-agent-data-plane (Team:Elastic-Agent-Data-Plane)

[mergify]

This pull request has not been merged yet. Could you please review and merge it @belimawr? 🙏