Add waiting list for item wishlists

[Encotric]

As a group member, I want to be able to add myself to an existing item wish on a group wishlist to be automatically on the waiting list when the item is available. Therefore, a group wishlist should have a button to add the currently logged-in user to the waiting list for this item.

Dependencies

Depends on:

• Add group wishlists #232
• Add Lending Process: Waiting List #18

Acceptance Criteria

• group members can add themselves to the waiting lists of items on the wishlist
• when the item becomes available, the waiting list for the item is has the same entires as the waiting list for the wish before