Add pages to consolidated object storage settings

What does this MR do?

Part of omnibus-gitlab#5577 (closed)

This MR allows consolidated object storage settings to be used for pages.

Currently, consolidate object storage configuration requires buckets for all enabled feature to be set.

That will prevent instances with consolidated configuration enabled from starting. So we add an exception for pages, and just printing a warning instead of raising the exception.

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