feat: Refactor SDK methods to use direct function exports instead of class methods
- Updated the SDK generation to export functions for API operations (e.g., addPet, updatePet) instead of using static class methods.
- Removed Angular service classes for Pet, Store, and User, simplifying the API interaction.
- Enhanced the Angular resource plugin to support customizable class and method name builders for generated resources.
- Adjusted method names in the generated Angular services to follow the new naming conventions.
- Updated the configuration types to include optional builders for class and method names.