### Description - Applies to both project merge request list view and group merge request list view. - Applies to all three tabs in the merge request list view, i.e. `open, merged, closed`. - Update the API to return this same information. * View who has approved a merge request, and who still needs to approve using a hover UI. ### Mockups * When the number of approvals has been met, show only those approvers <img src="/uploads/b3dd2cfb50087b2abac21049b242a8c1/hover-list-02.png" height="200" /> * When the number of approvals has not been met yet, show who has approved, and anybody else that can approve. <img src="/uploads/813fc9a5558b6a973b801a2c8f11d2d9/hover-list-01.png" height="200" /> * How it looks zoomed out. <img src="/uploads/ba1c1d91c416d69c23fb34eae393ec6e/merge-qeuest-list_approver-02.png" height="500" />