Improve UX for Group SAML Configuration page

What does this MR do?

Original issue: #207083 (closed)

This MR replaces switching off for dependent toggles with just keeping them disabled. It allows correctly handle default values (like prohibited_outer_forks being true as default) and also allows not to lose previous settings if main ones are temporarily disabled

Videos

Before	After
output	demo

Does this MR meet the acceptance criteria?

Conformity

• [-] Changelog entry
• [-] Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style 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

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team