add equiv check to filebeat as shipper test

[leehinman]

Proposed commit message

add document equivalency check to filebeat as shipper process integration test

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.

How to test this PR locally

Run go integration tests

cd x-pack/filebeat
mage goUnitTest

Just run this test

cd x-pack/filebeat
mage docker:composeUp
go test ./tests/integration -count 1 -tags integration -run TestShipperInputOutput

Related issues

• Closes Add document equivalency test case to end to end tests elastic-agent-shipper#290

[mergify]

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

💚 Build Succeeded

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Build stats

• Start Time: 2023-09-12T18:39:43.389+0000

• Duration: 115 min 13 sec

Test stats 🧪

Test	Results
Failed	0
Passed	28265
Skipped	2013
Total	30278

💚 Flaky test report

Tests succeeded.

🤖 GitHub comments

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To re-run your PR in the CI, just comment with:

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[leehinman]

@cmacknz or @pierrehilbert can you review? I think the change to go.mod triggered a review by Beats Tech Leads