codeintel: Make fake record for non-visible repos

[efritz]

Site-admins can no longer see private repos on Cloud, which means we return the wrong total count when listing uploads/indexes for repos that are not visible by the current user.

We should return fake records indicating that there is an upload or index record, but the details can't be seen by the current user.

[github-actions]

Heads up @macraig - the "team/code-intelligence" label was applied to this issue.