MR settings: Migrate to use SettingsSection and Crud components

...sets/javascripts/vue_shared/components/crud_component.vue

app/components/layouts/settings_section_component.haml

app/components/layouts/settings_section_component.rb

...quests/_merge_request_settings_description_text.html.haml

app/views/projects/settings/merge_requests/show.html.haml

...s/javascripts/approvals/components/approval_rules_app.vue

...omponents/security_orchestration/scan_result_policies.vue

...ts/javascripts/status_checks/components/status_checks.vue

...erge_requests/_merge_request_approvals_settings.html.haml

...quests/_merge_request_settings_description_text.html.haml

...gs/merge_requests/_suggested_reviewers_settings.html.haml

...gs/merge_requests/_target_branch_rules_settings.html.haml

.../frontend/approvals/components/approval_rules_app_spec.js

...nents/security_orchestration/scan_result_policies_spec.js

...c/frontend/status_checks/components/status_checks_spec.js

...ts/previews/layouts/settings_section_component_preview.rb

spec/frontend/vue_shared/components/crud_component_spec.js