Add check for github codeowners file

[jsoriano]

What does this PR do?

It adds checks for owners:

• All manifests in the repo must have a github owner.
• All packages must have an entry in .github/CODEOWNERS.
• Owner specified in the manifest must be one of the owners specified for a package in .github/CODEOWNERS.

Manual exceptions as multiple owners in the github file, or owners per subdirectory are still allowed.

How to test this PR locally

mage check

Related issues

• Continues with Add github codeowners #2631.

Screenshots

[elasticmachine]

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• Start Time: 2022-03-10T18:11:20.123+0000

• Duration: 91 min 24 sec

Test stats 🧪

Test	Results
Failed	0
Passed	4379
Skipped	7
Total	4386

🤖 GitHub comments

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[mtojek]

A few nit-picks, which can be ignored or considered as a further improvement.

[mtojek]

You may also want to improve the Jenkins side.

Consider the hadoop package, it contains a single package and CODEOWNERS. The CI will trigger tests for all packages as the CODEOWNERS file is touched.

[jsoriano]

I didn't find if go tests were executed in CI. As all the Go code is somehow related to the magefile, I am adding it here, but I guess this could be added somewhere in the Jenkinsfile too.