Add --optimize add-/cleanup-feed-permissions (backport #1612)

[mergify]

This is an automatic backport of pull request #1612 done by Mergify.
Cherry-pick of 1e410f5 has failed:

On branch mergify/bp/gvmd-20.08/pr-1612
Your branch is ahead of 'origin/gvmd-20.08' by 1 commit.
  (use "git push" to publish your local commits)

You are currently cherry-picking commit 1e410f56e.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   CHANGELOG.md

no changes added to commit (use "git add" and/or "git commit -a")

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/github/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally

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