Add privacy indicator to every protected document

[pferreir]

Every protected document should have some kind of indicator that makes it clear that it is not public. There should also be a way for the user to know why they have access to the document (if they are directly in the ACL, or trough group membership [and which group]).

[pferreir]

Even though these indicators have already been added to Indico, there are still some things that can be done, namely:

• Showing indication of protection inheritance chain ("you can access this content because you have access to 'ATLAS Meetings'")
• Indicate why the user has access to the category at the top of the chain ("you can access this because you are a member of atlas-access-protection")