WIP: Resolve "Download a folder from repository (not complete repository or single files)"

What does this MR do?

It adds a download folder feature in repository when a user is inside a subdirectory.

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

Why was this MR needed?

To add the said feature to fix #24704 (closed)

Screenshots (if relevant)

Before (including those if inside a subdirectory and not)

New feature (The menu when inside a subdirectory and not)

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• API support added
• Tests added for this feature/bug
• Conform by the code review guidelines
  • Has been reviewed by a UX Designer
  • Has been reviewed by a Frontend maintainer
  • Has been reviewed by a Backend maintainer
  • Has been reviewed by a Database specialist
• Conform by the merge request performance guides
• Conform by the style guides
• Conform by the database guides
• If you have multiple commits, please combine them into a few logically organized commits by squashing them
• Internationalization required/considered
• End-to-end tests pass (package-and-qa manual pipeline job)

What are the relevant issue numbers?

Closes #24704 (closed)