merge account feature

create a management command to assign all data auctiontos, invoices, lot seller/winners, club memberhips, bapawards, and anything else that seems like it should be moved from one user to another put this as a method in userdata, merge_into(self, user_to_merge_to) so we can use it again in the future if needed, but for now I just want a management command like this: empty_account_and_move_data user_to_empty user_where_it_should_go do not delete the original user, just empty their stuff