To investigate: permission issues when sharing

[ntarocco]

Scenario: a CERN project/video is shared with an user who is not part of the list of users allowed to use/edit CERN videos, defined via the categories.json. In this case, the new user cannot change restrictions.

If easy (and it does not create permission issues), we should:

• take the list of users in the categories config
• add any other user added via Share tab

If hard, close this issue.