Display tier and version to users

There should be a way for every user of GitLab to know which tier and version they are on because this affects which features they have access to. Our docs list which tier+version is needed to have access to particular features, but there's no way for a user to make use of this info unless they are also an admin.

Tier = Core, Starter, Premium, Ultimate, Free, Bronze, Sliver, Gold Version = 11.4.0, 11.3.4, etc.