Allow sharing of published records with non-CERN users

[zzacharo]

Use case

As a user, I would like to share my restricted published video with non-CERN personnel.

Context

Currently, the system does not distinguish upload and read/download permissions and because of that, the restricted content can only be shared among logged-in users. At the moment, we allow on the SSO level only CERN primary accounts to login, as CDS Videos is CERN's institutional repository and its mission is to archive and disseminate the organization's output and only that.
That said, the use case of being able to share content with people who do not have a CERN account is valid and needs to be addressed.

Requirements

SSO

We need to allow external accounts to be able to login, i.e adjusting te Minimum Level of Assurance.

Codebase

• Only CERN primary accounts are allowed to upload any content in the platform.
• External accounts can login, but cannot upload any content.
• External accounts can see restricted content that is shared with them.
• We need to ensure that the cern users and cern groups endpoints are adapted to check that you have a permission to submit to the platform i.e you have a CERN primary account.