Prioritization of Epics should also prioritize the children issues

When viewing Epics in the Epic panel and adjusting their priorities up and down, this does nothing to the priorities of the related children of the Epics.

The Epic could be moved to the top of the panel, but its children keep in various positions in the backlog.
Instead of sending each of those children to the top, customers would drag and Epic from a lower position in the epics panel to the first spot, and then all of its children will be moved to the top of the backlog as well.