[front] Insufficient access rights for study: display a clear message

[sylvlecl]

Problem Statement

When trying to display a study for which the user does not have read access, the user gets an infinite waiting cursors, instead of getting an error message or 404.

Proposed Solution

In the case where the user tries to access a study for which he does not have read access, we should display a clear message in the panel, either:

• stating that he has insufficient rights
• or even just saying that the study does not exists

[laurent-laporte-pro]

We can't say that the study doesn't exist because it actually exist. But we can say something like "access denied".

When a user attempts to access a page or resource for which they don't have permission, the server will typically return a 403 Forbidden response to indicate that access is denied.

[sylvlecl]

404 could be relevant if don't want to leak the information that such a study exists.
But in our case I agree that it does not seem important.