Fix user auto-suggest input / do not explicitly exclude group IDs

[tillprochaska]

The reason behind excluding specific IDs is to not suggest users and groups that are already associated with the collection. However, the /roles/_suggest endpoint returns only users, never groups, so there is no point in explicitly excluding groups. Fixes #3820.

In case a collection is shared with a large (200+) number of individual users, this may cause the same error as reported in #3820. However, this would require explicitly sharing a collection with such a large number of users whereas #3820 affected any collection, even if it wasn’t shared with anyone. Also, I don’t think there has been a use case for sharing a collection with so many individual users, and probably using groups would be more appropriate in such a situation.

You can verify this by adding yourself to a few user groups:

aleph creategroup test1
aleph creategroup test2
aleph creategroup test3
aleph useradd test1 user@example.org
aleph useradd test2 user@example.org
aleph useradd test3 user@example.org

• Log out and in to recreate your session.
• Create a new investigation and open the share dialog.
• Open the network tab in the browser developer tools.
• Type something into the auto-suggest input.
• You should be able to see a request to /roles/_suggest?exclude:id=123&prefix=test (where 123 is the ID of your user). There shouldn’t be any additional exclude:id params.