Improve iteration filter dropdown

Everyone can contribute. Help move this issue forward while earning points, leveling up and collecting rewards.

• Close this issue

As a follow-up to #118742 (closed), we can improve the sorting of the iteration dropdown

@acroitor also suggested that we could add a "Current" option similar to the "Upcoming" / "Started" we have for milestones. We probably could have a "Next" option too.