More clearly communicate that a milestone is expired
Problem to solve
As a follow up to gitlab-com/gl-infra/delivery#610 (comment 267007310), there is currently no visual indicator when selecting a milestone whether it is expired or not. This could inadvertently lead to issues and merge requests being assigned to the incorrect or outdated milestone.
- Move expired milestones to the bottom of the milestone list to discourage adding issues to expired milestones
(expired)next to expired milestones within the milestone select field: