Organizations: Make the option "Enforce organization data ownership" more selective

Current implementation

When one chooses to enable the policy "Enforce organization data ownership", regular users cannot have their own Vault anymore, they're forced to save everything in the organization.
For admins/Owners, this doesn't apply, they still have their private vault.

Problems

There might be a handful of users in the organization that would need a private vault, but cannot be justified to give them admin privileges. Currently you only have the options:

1. Disable "Enforce organization data ownership" entirely
2. Make them Admins

Suggestion

It would be useful to have a more selective way of deciding wheter a user can have a private vault or not.