Grafana 8.3.5 introduced a new CSRF protection mechanism that requires the value of the Host HTTP request header to be preserved from the original client request. https://github.com/grafana/grafana/issues/45117#issuecomment-1033842787
This commit introduces the *grafana* role and the corresponding `grafana.yml` playbook. The role installs Grafana using the system package manager, and configures the server (including LDAP authentication).
