lakectl abuse link-same-object

[nopcoder]

Abuse command that will get a link to stage and link object in parallel. The command was created to capture the case of parallel write to the same key. In our pg staging implementation while using serializable transaction this cased failure when the number of retries reached the current max.

Close #3854

[nopcoder]

Thanks - a bit confused about the list/link terminology

Thanks for the review - update the flags description to reflect the operation