Add warning about failing to obtain LE certificates to pages setting page

What does this MR do?

Part #30146 (closed)

Adds warning on the bottom of this screenshot by analogy with verification warning:

domain details is clickable and leads to the domain edit page.

The retry button and warning on the domain page will be added in another MR.

Everything is behind the feature flag at the moment.

Warnings are never shown together since required verification blocks LE process and verification warning takes precedence.

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