Adding aws-s3 metric for delayed time

[kgeller]

What does this PR do?

Adding the metric to answer how delayed are the SQS messages being received

For messages that are being received the first time (ApproximateReceiveCount==0) what is the moving average delta between the message's SentTimestamp and now. This can indicate it the input is falling behind without needed to capture queue metrics.

Why is it important?

This will let us observe how much lag there is in receiving SQS events by measuring delta between the time the SQS message was written to the queue to the time Filebeat receives it.

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

• Verify name of the new metric

How to test this PR locally

http://localhost:5066/dataset?pretty now includes the following

"sqs_lag_time": {
      "histogram": {
        "count": 1,
        "max": 123893321000,
        "mean": 123893321000,
        "median": 123893321000,
        "min": 123893321000,
        "p75": 123893321000,
        "p95": 123893321000,
        "p99": 123893321000,
        "p999": 123893321000,
        "stddev": 0
      }
    },

Related issues

Relates https://github.com/elastic/security-team/issues/5526

[mergify]

This pull request does not have a backport label.
If this is a bug or security fix, could you label this PR @kgeller? 🙏.
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

[elasticmachine]

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• Start Time: 2023-01-27T17:53:13.001+0000

• Duration: 129 min 27 sec

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Test	Results
Failed	0
Passed	5064
Skipped	350
Total	5414

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[mergify]

This pull request is now in conflicts. Could you fix it? 🙏
To fixup this pull request, you can check out it locally. See documentation: https://help.github.com/articles/checking-out-pull-requests-locally/

git fetch upstream
git checkout -b s3-metrics upstream/s3-metrics
git merge upstream/main
git push upstream s3-metrics

[elasticmachine]

Pinging @elastic/security-external-integrations (Team:Security-External Integrations)