Indicate expired invitations in the Manage Users page.

Problem: We have had issues with new users trying to accept a Prodify invitation after it has expired - we have extended the expiry window to 30 days but it is not clear after an invite has been sent, when this will expire.

Solution: In the manage users table add a column showing the expiry date of the invitation - once this date has been reached this should indicate that the invitation has expired (red expired text)