If user unsubsrcribes from a resource that they no longer have
access to they should not be revealed the resource path, but be
redirected to app root instead.

https://gitlab.com/gitlab-org/gitlab-ce/issues/64938

This prevents a MITM attack where attacker could
still access Git repository if any jobs were
running long enough.

Fix rubocop offences and add changelog

Add email_verified key for feature specs

Add code review remarks

Add code review remarks

Fix specs

Label events may use cross-project or cross-group references,
if the projects are not accessible by user, we don't show these
label events.

[ci skip]

[ci skip]

[ci skip]