Support SendURL for performing indirect download of artifacts if clients does…

What does this MR do?

This makes a use of Workhorse feature SendURL which makes Workhorse to proxy response for given request.

We use that for Artifacts that are being downloaded by runner, because older runners cannot validate certificate of remote server when trying to download the artifacts.

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• API support added
• Tests added for this feature/bug
• Review
  • Has been reviewed by Backend
• Conform by the merge request performance guides
• Conform by the style guides
• Squashed related commits together

What are the relevant issue numbers?

https://gitlab.com/gitlab-com/infrastructure/issues/3618