Add feature specs for Security Configuration page

What does this MR do?

Add basic Security Configuration feature spec

This is to support the rearchitecturing work in &5460.

Addresses #322462 (closed).

Screenshots (strongly suggested)

n/a

Does this MR meet the acceptance criteria?

Conformity

• [-] Changelog entry
• [-] 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