Draft: Enable Security Configuration for Core users by default [RUN ALL RSPEC] [RUN AS-IF-FOSS]

What does this MR do?

Enable CE Security Configuration page by default

Addresses #294076 (closed), part of &4787.

Draft

~~This is in draft, as it's blocked by !53412 (merged), which implements the frontend that this MR enables by default.~~

This is in draft as we've decided not to merge this until at least !53919 (merged) has merged, and this feature has been enabled in production for some period of time.

Testing locally

1. Merge in !53412 (merged) locally
2. Visit any project you have developer access to that isn't on an Ultimate license
3. Click Security & Compliance > Configuration in the sidebar

Note: there is a known bug whereby the sidebar entry does not appear on EE instances on the Free tier; see linked thread for the pending fix.

Screenshots (strongly suggested)

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