Allow groups to disable 2FA requirement for subgroups - changing subgroups settings

What does this MR do?

As another part of effort to introduce new setting that prohibits subgroups for setting up their own 2FA if parent group does not allow it.

This change allows to change a setting on the top-level group and it causes chain reaction to update the subgroups and their members.

UI will come in the next MR.

Screenshots

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

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

related to #215697 (closed)