Populate a list of machines with machines that might not yet be persisted on disk

What does this MR do?

This tries to solve the issue described in: #2342 (comment 69862409).

This also solves issues with #3424 (closed) since this merge request prevents from creating too many instances so we don't consume the AWS API that much and prevent from being rate limited.

Does this MR meet the acceptance criteria?

• Documentation created/updated
• Tests
  • Added for this feature/bug
  • All builds are passing
• Branch has no merge conflicts with master (if you do - rebase it please)

What are the relevant issue numbers?

Closes #2342 (closed) Related to #3424 (closed)