Re-position live-region to remove duplication
Re-position live-region to remove duplication

Adding a visually hidden live-region creates
duplication in the HTML. End result for users of
screen readers are that you get the same text read
out twice.

This adds `aria-hidden` to hide the visible
version and re-positions the live-region one next
to it. That means the live-region text appears in
the same place in the document order as the
visible one so things are announced as expected.

alphagov/notifications-admin,alphagov/notifications-admin,alphagov/notifications-admin,alphagov/notifications-admin