WIP: Separate access request tables from members

What does this MR do?

Moves project member requests and group member requests into their own tables.

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

Why was this MR needed?

So requests don't need to be filtered out of member queries.

Screenshots (if relevant)

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 #30704 (moved)