Space sharing can only be done by collection/dataset owner

[ocaisa]

Describe the bug
An admin or editor of a space cannot share a dataset/collection with another space. This only seems possible if the user is the owner (and in superadmin mode)

To Reproduce
Steps to reproduce the behavior:

1. Enable space sharing plugin
2. Click on '....'
3. Scroll down to '....'
4. See error

Expected behavior
A space editor or admin should be able to add the dataset/collection to another space.

Screenshots

When the user (a space administrator) is the dataset owner:

When the same user does not own the dataset:

Desktop (please complete the following information):

• OS: Windows 11
• Browser: Chrome
• Version: latest