Show security reports summary in pipelines' Security Dashboard

• Related issue: #222374 (closed)

What does this MR do?

This removes the vulnerability and scanned resources counts from the Pipeline Security Dashboard's filters in favor of a dedicated SecurityReportsSummary that takes care of displaying the information for each report type above the dashboard.

Note: when a given scanner detected 0 vulnerabilities, we want to show that information. However, scanners that aren't configured currently report 0 vulnerabilities, which results in slightly misleading information in the summary as we can't tell non-configured scanners from the ones that didn't detect any vulnerabilities. This will be addressed in a follow-up backend issue: #223073 (closed)

How to test this?

• Enable the feature flag:

echo "Feature.enable(:pipelines_security_report_summary)" | spring rails c

• Sign-in as the root user
• Visit a pipeline that has some security scanners setup an navigate to the Security tab

Screenshots

Summary expanded	Summary collapsed

Recording

summary

Does this MR meet the acceptance criteria?

Conformity

• [-] Changelog entry (not required as this is behind a feature flag)
• [-] Documentation (if required) (not required as this is behind a feature flag)
• Code review guidelines
• [-] Merge request performance guidelines
• Style guides
• [-] Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• [-] Tested in all supported browsers
• [-] Informed Infrastructure department of a default or new setting change, if applicable per definition of done