No activity for applicable users in global external storage

[PVince81]

Steps:

1. Setup an external storage, for example "/sftp" applicable to two users "user1" and "user2"
2. Login as "user1"
3. Create a folder "/sftp/test"
4. Check activities
5. Login as "user2"
6. Check activities

Expected result

Both user1 and user2 have an activity for "/sftp/test"

Actual result

Only the creator, user1, has an activity for "/sftp/test".

@DeepDiver1975

@pmaier1 another potential debt item

[PVince81]

I suspect a bug in the code that gets all applicable users. In the encryption code this required custom code specific for external storages. Ideal would be to have a single API in core to get all users that have access to a file/folder for apps like encryption and activity to use.