Allow specification for file extension to be used in import statement paths for files created by code generation

[TheMartianMaker]

Feature Request:

• Option to specify a file extension: Add a configuration option to specify the file extension (e.g., .js, .ts) that should be used in all import statements within the generated files.
• Consistent import paths: Ensure that all import statements in the generated files use the specified file extension.

Use Case: For ESM projects, it is often required to include file extensions in import statements. Currently, developers have to manually update the import statements in the generated files to include the necessary file extensions. This feature would automate that process and ensure consistency across the codebase, which is crucial for maintaining proper module resolution in ESM environments.