API fuzz - configuration screen - Create configuration page

What does this MR do?

This boilerplates a new page to host the upcoming API fuzz testing configuration form and links to it from the Security Configuration page.

How to test this?

1. Enable the feature flag.

echo "Feature.enable(:api_fuzzing_configuration_ui)" | rails c

2. Navigate to a project's Security Configuration page at /:namespace/:project/-/security/configuration.
   • You should see the Enable link in the API Fuzzing section.
   • Clicking on the link brings you to the, currently empty, API fuzz testing configuration page.

Screenshots (strongly suggested)

Before	After

Does this MR meet the acceptance criteria?

Conformity

• [-] Changelog entry (behind a feature flag)
• [-] Documentation (if required)
• 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

Related to #299125 (closed)