Implement the backport

Problem/Motivation

In Drupal 11.3, field.storage.node.body was moved out of the Node module into a new node_storage_body_field sub-module (#3447617).

Contributed modules that ship node types with a body field must now declare a dependency on node_storage_body_field to ensure the field storage
config exists when their module is installed. However, adding this dependency breaks installation on Drupal 10.x and 11.0–11.2, where the sub-module does not
exist.

Moving field.storage.node.body to config/optional does not work reliably. Drupal's
ConfigInstaller::checkConfigurationToInstall() validates all config/install dependencies for all modules being installed in a single operation — including during install profile execution and drush en with dependencies. Optional config is either deferred (during profile install) or only processed after all config/install is validated, causing UnmetDependenciesException failures.

Steps to reproduce

1. Have a contributed module that ships a node type with a body field (e.g. field.storage.node.body in config/install).
2. Add node_storage_body_field:node_storage_body_field as a dependency in the module's .info.yml to support Drupal 11.3.
3. Attempt to install the module on Drupal 10.x or 11.0–11.2 — installation fails because node_storage_body_field does not exist.
4. Alternatively, move field.storage.node.body to config/optional and attempt to install the module as part of a profile or via
   drush en with dependencies — installation fails with UnmetDependenciesException.

Proposed resolution

Create a forward-compatibility polyfill module (drupal/backport_node_storage_body_field) with two major versions:

• 1.x (Drupal 10.x / 11.0–11.2): Provides a minimal node_storage_body_field module that ships field.storage.node.body
  in its config/install, mirroring the behavior of the core sub-module added in 11.3.
• 2.x (Drupal 11.3+): Empty metapackage. Core already provides node_storage_body_field, so this package is a no-op.

Contributed modules can then:

1. Add "drupal/backport_node_storage_body_field": "^1 || ^2" to their composer.json.
2. Add node_storage_body_field:node_storage_body_field to their .info.yml dependencies.
3. Remove field.storage.node.body from their own config/install.

Remaining tasks

• Create the 1.x branch with the polyfill module and field.storage.node.body config.
• Create the 2.x branch with the metapackage.
• Tag initial releases.
• Update consuming modules to use the polyfill.

User interface changes

None.

API changes

None.

Data model changes

None. The polyfill provides the same field.storage.node.body config that core's node_storage_body_field sub-module provides in 11.3.