Segregate feature flag control for Compliance frameworks and Pipeline configuration

What does this MR do?

This MR segregates the availability of Compliance Framework and Compliance Pipeline configuration feature, by controlling them by two separate feature flags.

This will help in rolling out Compliance Framework and Compliance Pipeline configuration features independently.

Feature	Feature flag name
Compliance frameworks	ff_custom_compliance_frameworks
Compliance Pipeline configuration	ff_evaluate_group_level_compliance_pipeline

Policies are updated to use the respective FF name.

Mentions #287779 (comment 528314432)

Screenshots (strongly suggested)

Compliance Framework Create / Edit form based on enablement of ff_evaluate_group_level_compliance_pipeline feature flag:

Enabled	Disabled

Does this MR meet the acceptance criteria?

Conformity

• 📋 Does this MR need a changelog?
  • I have included a changelog entry.
  • I have not included a changelog entry because the feature is gated.
• 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