Security Dashboard improvements
### Description Improvements after Security Dashboard MVC: https://gitlab.com/groups/gitlab-org/-/epics/161, based on the product discovery in https://gitlab.com/gitlab-org/gitlab-ee/issues/7091. The Security Dashboard could be split into two different panels: 1. the Security Overview, where metrics are presented (target: Director of Security) 1. the list of vulnerabilities, where specific actions can be taken (target: Security Specialist)
epic