Initialize Varbase API Base recipe and migrate default API recipe

Problem/Motivation

The default API recipe is currently defined inside the varbase_api module, which mixes feature implementation with installation recipes.

With the move toward clearer separation of concerns and reusable base recipes, the API setup should live in a dedicated Varbase API Base recipe, allowing:

• Cleaner architecture
• Easier reuse by other Vardot distributions or recipes
• Better alignment with Drupal Recipes best practices

Proposed resolution

#3561802: Start an 11.0.x branch for Varbase with Recipe Installer Kit

• Introduce a new Varbase API Base recipe and migrate the existing default API recipe from the varbase_api module into it.
• Creating a new recipe named Varbase API Base
• Moving all API-related module installs, config imports, and actions into the recipe
• Keeping varbase_api focused on functionality rather than installation logic

Recipe Definition

• The new recipe (recipe.yml) will:
  • JSON:API
  • Simple OAuth
  • OpenAPI (JSON:API, REST, Redoc, Swagger)
  • REST UI
  • JSON:API Extras & Defaults
• Install required API, authentication, and documentation modules:
• Import default configuration for all related modules
• Apply configuration actions:
  • Configure jsonapi_extras.settings with a default /api prefix and safe defaults
  • Grant API and documentation permissions to the site_admin role

Remaining tasks

• ✅ File an issue about this project
• ✅ Addition/Change/Update/Fix to this project
• ✅ Testing to ensure no regression
• ✅ Automated unit/functional testing coverage
• ✅ Developer Documentation support on feature change/addition
• ➖ User Guide Documentation support on feature change/addition
• ➖ UX/UI designer responsibilities
• ➖ Accessibility and Readability
• ✅ Code review from 1 Varbase core team member
• ✅ Full testing and approval
• ✅ Credit contributors
• ✅ Review with the product owner
• ✅ Update Release Notes
• ❌ Release varbase-11.0.0-alpha1, varbase_starter-1.0.0-alpha1, varbase_api_base-1.0.0-alpha1

User interface changes

• N/A

API changes

• N/A

Data model changes

• N/A

Release notes snippet

• feat: #3566427 Initialize Varbase API Base recipe and migrate default API recipe