Add support for verifying remote uploads, artifacts, and LFS objects in check rake tasks

What does this MR do?

Adds support for verifying remote files in these rake tasks:

rake gitlab:artifacts:check                                         # GitLab | Artifacts | Check integrity of uploaded job artifacts
rake gitlab:lfs:check                                               # GitLab | LFS | Check integrity of uploaded LFS objects
rake gitlab:uploads:check                                           # GitLab | Uploads | Check integrity of uploaded files

Actually fixes artifacts check since it should have been, but wasn't, excluding remote files.

Are there points in the code the reviewer needs to double check?

Why was this MR needed?

Since bugs have been recently fixed Geo attachment replication, we would have to wait and see if all bugs have been fixed. But object storage for uploads is ready, so we will be enabling it instead. This MR will help us check the integrity of uploads in object storage.

Screenshots (if relevant)

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Tests added for this feature/bug
• Conform by the code review guidelines
  • Has been reviewed by a Backend maintainer
• Conform by the style guides
• If you have multiple commits, please combine them into a few logically organized commits by squashing them

What are the relevant issue numbers?

Resolves https://gitlab.com/gitlab-org/gitlab-ce/issues/47139