Package: combine single-use methods, always signal operation finished

[danirabbit]

We can definitely go further with refactoring, but wanted to stop before it got too complicated while also DRYing for #2394

• Combines the single-use prepare and clean_up functions into perform_operation
• Make sure we always send operation_finished in perform operation
• Fix early returns and throw errors

[leolost2605]

LGTM thank you!