Bag swapping automation

[veechs]

What will your feature request solve?

Bag swapping is a pain in Vanilla since the bag has to be empty, often requiring a lot of manual item moving.

Describe the solution you'd like

Automatically reshuffle items as needed when a bag swap is attempted. It would be even better if the Bank could be used as temporary storage when there's not enough space in Bags and vice-versa.

Another neat related feature would be to have a way to empty a bag.

Describe alternatives you've considered

Swapper exists (I've never personally used it).

Additional context

Requested here by @Nikki1993.

[veechs]

Transferred to #61 - closing discussion.