Workflow action not warn on same workflow validation if not advance state

The same user can perform multiple workflow validation on multi-user validation if the workflow has not advance state. This means that the same user can go back to the same document and perform validation multiple times on the same document until the document moves to the next workflow state.

note: once it does move state, the user will get "This workflow action is no longer valid for the document (it may have already been executed)."

Ideally, if the user already has perform the workflow action, it should be a warning on subsequent attempts to re-validate the document just like when the document has advance state.