Fix to-do assignment for subsequent approvals required on same MR
When an approver is initially assigned on a MR, it creates a to-do for the approval (expected), however if they approve the MR the to-do is removed and a new one is not created when new approval is required.
Steps to reproduce
As a developer, I open MR. Tag people for review, I require 2 approvals. Person A approves it, which removes it as a to-do for person A. Person B asks for a change. I make the change, which clears the approval from person A but does not re-add it as a to-do for them.