Move test coverage for Enforced SSO Access to feature level

What does this MR do?

Adds coverage at feature level for Enforced SAML SSO and removes the end-to-end tests.

Closes: #205455 (closed)

Conformity

• [-] Changelog entry
• [-] Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• [-] Database guides
• [-] Separation of EE specific content