* Pass role to Grafana using auth proxy
By default, the role will be applied to the default org of the user.
If the request uses the standard header "X-Grafana-Org-Id", the role will be applied to the specified org
Tested in both unit test and manually E2E
* Address comment: only allow the user role to be applied to the default org
Co-authored-by: Leonard Gram <leo@xlson.com>