Storage enforcement based on purchased storage

What does this MR do?

Part of https://gitlab.com/gitlab-org/gitlab/-/issues/247449

Depends on !43322 (merged) and !44376 (merged)

Add storage enforcement based on purchased excess storage within the RepositorySizeChecker when the feature flag additional_repo_storage_by_namespace is enabled. The storage will be locked when the repository size is greater than the actual size limit (project level or namespace level when nil) and there is no more excess storage than additional purchased storage available.

The exceeded size will be calculated by

current repo size + new change size + total excess size - actual size limit - additional purchased storage

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