Users can specify --run-id for a previously existing run, and Metaflow happily continues

[emattia]

If run 123 has failed on any step, and a user accidentally does resume --run-id 123 instead of resume --origin-run-id 123, they will get an unexpected UX where Metaflow does the resume from a run that may not be the same one (if their desired origin run id is from Argo, for instance), and the backend is now polluted by the mixing of task execution data from the parent and resume runs. Metaflow should catch the foot gun before the resume run is created on the duplicate --run-id.

[vanshapple]

Hi! I would love to work on this by adding validations when a user specifies a --run-id that already exists.