Rollback project folder move after error in Projects::TransferService

What

Moves repo data back to original location if there is an error during the transfer.

Why

Previously, an error when moving a project would break the repo. This was because database changes would get rolled back while leaving the project in the updated location.

Acceptance criteria

• Changelog entry added, if necessary
• Documentation updated
• Tests added for this feature/bug

What are the relevant issue numbers?

Closes #30213 (closed)