Support Epic filtering on team-managed boards

Use-Case:

• We plan Epics on the Roadmap.
  • Some may already be complete.
  • We can filter to see the "In progress" Epics, and avoid seeing Epics that are done or are in the planning / to-schedule stages.
• When we looking at issues on the Board, we want to filter and look at only issues in "In progress" Epics. However, we can't filter in the same way, so we see all issues in all Epics. We can consider some workarounds to achieve the same effect:
  • If we try to use the "Backlog" feature, we can move issues up to the "Board" from the "Backlog", then they appear in the Board. However, once an epic is done, we have to move all the issues back into the "Backlog" to make them stop appearing on the board. We also have to manage this issue-by-issue instead of at the Epic-level which is what we'd want.
  • If we try to use the "Sprint" feature, we can run a single sprint forever and move issues in and out of the board, but this is even more awkward than using the backlog.
  • We can "know" what the "In progress" Epics are, and filter for those Epics using the Epics filter. But this needs to be kept in sync with the status changes of the Epics. For now, this seems like the easiest workaround.

Requested feature:

• Add an "Epic Status" filter for the Board that works like the "Status" filter on the Roadmap.
• Bonus if these two filters are linked/are the same so that when you update the filtering conditions of the Board and go back to the Roadmap (or vice versa), the updated filtering conditions are also on the Roadmap.