Context

Ref: #24493

In preparation for the new backend system stable release, we will deprecate the backend-common package.

Description

All service implementations currently exported from the backend-common package should be extracted to individual subpaths on the backend-defaults package.

Acceptance criteria

• Extracted code should be re-exported from the new module in the old package
• Deprecation exports in the old packages must be declared in a deprecated.ts file
• Deprecation exports should be annotated with @deprecated and contain a comment explaining their replacements
• Other packages' import statements should be updated to use bindings from the new package
• Documentation examples should be revisited to use code from the new package instead