Use replicaset and Job MetaGen based on watchers

[ChrsMark]

Respective PR for elastic/elastic-agent-autodiscover#44 part of elastic/elastic-agent-autodiscover#31.

Blocked until elastic/elastic-agent-autodiscover#44 is merged and a new version of the autodiscovery library is released.

How to test this PR locally

1. Build Agent using DEV=true PLATFORMS=linux/amd64 PACKAGES=docker mage -v package
2. Build a custom docker image out of the previous build using the file from build/package/elastic-agent/elastic-agent-linux-amd64.docker/docker-build directory.
3. Load the image into a kind cluster using kind load docker-image custom-agent
4. Deploy Agent standalone on k8s using the custom image
5. Verify that k8s autodiscovery work as expected (with the container logs part for example) and that job/cronjob , deployment/replicaset metadata are being populated properly.

Screenshots

[mergify]

This pull request does not have a backport label. Could you fix it @ChrsMark? 🙏
To fixup this pull request, you need to add the backport labels for the needed
branches, such as:

• backport-v./d./d./d is the label to automatically backport to the 8./d branch. /d is the digit

NOTE: backport-skip has been added to this pull request.

[elasticmachine]

💚 Build Succeeded

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Build stats

• Start Time: 2023-05-31T09:04:25.933+0000

• Duration: 19 min 49 sec

Test stats 🧪

Test	Results
Failed	0
Passed	5663
Skipped	19
Total	5682

💚 Flaky test report

Tests succeeded.

🤖 GitHub comments

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

• /test : Re-trigger the build.

• /package : Generate the packages.

• run integration tests : Run the Elastic Agent Integration tests.

• run end-to-end tests : Generate the packages and run the E2E Tests.

• run elasticsearch-ci/docs : Re-trigger the docs validation. (use unformatted text in the comment!)

[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 rs_cj_watchers upstream/rs_cj_watchers
git merge upstream/main
git push upstream rs_cj_watchers

[mergify]

This pull request does not have a backport label. Could you fix it @ChrsMark? 🙏
To fixup this pull request, you need to add the backport labels for the needed
branches, such as:

• backport-v./d./d./d is the label to automatically backport to the 8./d branch. /d is the digit

NOTE: backport-skip has been added to this pull request.

[elasticmachine]

🌐 Coverage report

Name	Metrics % (covered/total)	Diff
Packages	98.611% (71/72)	👍
Files	68.273% (170/249)	👍
Classes	67.021% (315/470)	👍
Methods	53.678% (956/1781)	👍
Lines	39.493% (11020/27904)	👎 -0.049
Conditionals	100.0% (0/0)	💚