## Context
We have a non-nullable constraint on authorId in attachments and
documents, until we have soft-deletion we need to handle deletion of
workspace-members and their attachments/documents.
This PR introduces pre-hooks to deleteOne/deleteMany
This is called when a user deletes a workspace-member from the members
page
Next: needs to be done on user level as well. This is called when users
try to delete their own accounts. I've seen other issues such as
re-creating a user with a previously used email failing.
fe758e193f