Add user info on dashboard views once logged in

[kvenkatrajan]

With oidc - user can be authenticated. Add user info as per issue comment: #3033 (comment)

CC: @drewnoakes

[drewnoakes]

There's some pending work here. The lack of a default authorization scheme in the web app's config means that the /signin-oidc response isn't being handled properly. We get an authentication cookie, but no claims or user details are available in the dashboard app. We need to find a workaround, or a way to reinstate a default authentication scheme that doesn't break either the frontend or OTLP auth.