Show latest security reports at project level

config/routes/project.rb

doc/user/project/img/project_security_dashboard.png

doc/user/project/index.md

doc/user/project/security_dashboard.md

...vascripts/pages/projects/security/dashboard/show/index.js

...vue_shared/security_reports/card_security_reports_app.vue

.../security_reports/components/empty_security_dashboard.vue

...vue_shared/security_reports/components/report_section.vue

...ue_shared/security_reports/split_security_reports_app.vue

ee/app/assets/stylesheets/pages/projects.scss

ee/app/assets/stylesheets/pages/security_reports.scss

ee/app/controllers/projects/security/dashboard_controller.rb

ee/app/helpers/ee/projects_helper.rb

ee/app/models/ee/ci/pipeline.rb

ee/app/models/ee/project.rb

ee/app/policies/ee/project_policy.rb

ee/app/views/projects/security/dashboard/show.html.haml

ee/app/views/projects/sidebar/_security_dashboard.html.haml

ee/changelogs/unreleased/6165_project_security_dashboard.yml

...ontrollers/projects/security/dashboard_controller_spec.rb