Show my approval status in merge request list (Web and API)

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.

• In the list view, for each merge request record, indicate:

  • I am not an eligible approver, or:
  • I am an eligible approver.
    • I have approved.
    • I have not approved (or previously removed my approval).

• The user of the API is what "I" reflects above.