refactor: decouple main function to allow custom distributions of the telegraf agent

[neelayu]

Required for all PRs

• [ ] Updated associated README.md.
• [x] Wrote appropriate unit tests.
• [x] Pull request title or commits are in conventional commit format

resolves #11851

[telegraf-tiger[bot]]

Thanks so much for the pull request! :handshake: :black_nib: Just a reminder that the CLA has not yet been signed, and we'll need it before merging. Please sign the CLA when you get a chance, then post a comment here saying !signed-cla

[telegraf-tiger[bot]]

Thanks so much for the pull request! :handshake: :black_nib: Just a reminder that the CLA has not yet been signed, and we'll need it before merging. Please sign the CLA when you get a chance, then post a comment here saying !signed-cla

[srebhan]

As mentioned in the corresponding issue (#11851) we do not want to provide an "app" you can run but rather a nice code organization to be able to write your own main. However, as mentioned in the issue, we will not guarantee any public interface.

This being said, I will close this PR as it does not provide the clear function (in their respective sub-packages) we would expect. Feel free to reopen this PR if you want to work on the mentioned code-reorganization or open a new PR!