Fix milestone order in project and issue edit lists to due_date

_Originally opened at !2579 by @olirogers._

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This MR orders the milestones by due date (earliest first) in the project and edit issue view. These suggestions were made be @orih in #6001 and fixes #6001.

This continues the work of !1934 to order milestones.

I found this annoying when creating milestones, found #6001 but no attached MR. This is my first for this project - comments and criticisms welcome.

See merge request !2780