New API End Point: Epic Position on Kanban Board

Proposal

Using the Kanban board, some customers order the epics/issues to prioritize their work. While the order is saved per view, this information is only available via the UI. Having an API endpoint that returns the order of epics within each column will allow teams to report on the prioritization and create automation based on the position within the column.

Today, this information lives in the DB within boards_epic_board_positions table under relative_position column. Also, the position of epics within the list is also returned within graphQL API, but it is the incorrect one.