Add `artifact` format

This is a general Merge Request template. Consider to choose a template from the list above if it will match your case more.

What does this MR do?

This is part of https://gitlab.com/gitlab-org/gitlab-ce/issues/46809

Which adds a proper support for multiple artifacts (types), with different formats (zip or raw), and so-on.

This is a part of https://gitlab.com/gitlab-org/gitlab-ce/issues/46809

• Gitlab-rails: https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/20293
• Gitlab-workhorse: gitlab-workhorse!269 (closed)
• Gitlab-runner: here

Does this MR meet the acceptance criteria?

• Documentation created/updated
• Tests
  • Added for this feature/bug
  • All builds are passing
• Branch has no merge conflicts with master (if you do - rebase it please)

What are the relevant issue numbers?

Related to https://gitlab.com/gitlab-org/gitlab-ce/issues/46809