Resolve "Improve compliance frameworks form UI/UX"

What does this MR do?

This MR resolves the following issues with compliance frameworks form UI/UX:

1. (!55592 (dea5a783)) The add forms submit button should say "Add framework" not "Save changes"
2. (!55592 (c48bd673)) On successful submission of the form, the form should not be reshown while waiting for the redirection to take place
3. (!55592 (322d4fb9)) The success banner on the listing is marked as dismissable but doesn't actually dismiss: !54224 (comment 515680449)

Setup & Testing

1. Enable the development feature flag in rails console: Feature.enable(:ff_custom_compliance_frameworks)
2. Navigate to a group's general settings [GDK_HOST]/groups/gitlab-org/-/edit#js-compliance-frameworks-settings
3. Add a compliance framework

Screenshots (strongly suggested)

Button text

Before	After

Loading behaviour

Before	After

Alert dismiss

Before	After

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 hidden behind a feature flag.
• [-] 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 #321974 (closed)