Improvement drop-down menu which is displayed when clicking on the name of the logged in user

[Kami]

Right now when you click on the name of the logged in user, a drop down menu shows with a "Sign out" link.

The link doesn't look much like a link and the whole dropdown also doesn't look much like dropdown (imo) so I think it would be good to restyle it a bit to make it immediately obvious it'a drop down menu with a sign out link.

Eventually I could also see us adding more links there - view profile info, view auth info, view assigned RBAC roles, etc.