Feature: Shared wishes for multiple users

[shoneg]

Is your feature request related to a problem? Please describe.
My girlfriend and I have some wishes for gifts that apply to both of us. For example, cooking supplies. Currently, there is no way to enter a wish that ensures not both of us will receive the same item and that neither of us can see when it is claimed.

Describe the solution you'd like
I see two possible solutions, but I don't know which would be better.

1. Currently, it is possible to assign a wish to multiple lists. This feature could be expanded so that you can allow specific people to share wishes with a specified list. Then, I could list a wish on my own list and on my girlfriend's list.
2. Similar to the managers feature, you could create a list where multiple people are owners. This way, none of the owners can see claims or claim items themselves.

Describe alternatives you've considered

1. Use the existing managers feature. Then, one of us sees that the wish items have been claimed.
2. We both add the wish to our private lists and include in the description that it is for both of us. However, there's still a risk that the item will be claimed by two different people because they might overlook the hint. Additionally, there's the problem that one of us can see when the item is claimed on the other's list.