WIP: Provide tagger information on Tags API

What does this MR do?

It includes the name and email of the author of an annotated tag and the time of the tagging to the Tag API.

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

Yes. I'm writing them down and I'll update this section ASAP.

Feedback on this ongoing work is more than welcome. :-)

Why was this MR needed?

I'll update this section with a short summary. For now, please see issue #33021 (moved) for more information.

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• API support added
• Tests
  • Added for this feature/bug
  • All builds are passing
• Conform by the merge request performance guides
• Conform by the style guides
• Branch has no merge conflicts with master (if it does - rebase it please)
• Squashed related commits together

What are the relevant issue numbers?

Closes #33021 (moved).