chore(order/bounded_order): split (#17730)
The file `order.bounded_order` was over 2000 lines long and I wanted to port a small part of it in the middle so I've broken it into four files `order.bounded_order`, `order.with_bot`, `order.prop_instances` and `order.disjoint`. No lemmas should have been added or removed. Because `order.bounded_order` contains less than before I had to add a few more imports to other files.
