Separate subdirectory for result types

[alzex3]

Dear Maintainers,

I am excited to propose an enhancement to library, which I believe will improve its usability.

Issue Addressed:
Currently, the library's hundreds of modules, including client enums, inputs, fragments, and the client itself, are housed in a single package directory. More information is available in the issue.

Proposed Change:
To address this, I have implemented a feature that allows result types to be saved into a separate subdirectory. This feature is disabled by default and have no breaking changes for current users.

Implementation Details:

1. Direct Integration into Client Generator: Recognizing the limitation of being unable to save result types into a different directory without modifying package module, I've directly incorporated the necessary logic into the client generator.
2. New Configuration Option: A new parameter, result_types_directory_name, has been introduced. Users can specify the name of the subdirectory for result types using this parameter. If this parameter is omitted or left empty, the result types will be stored in the package root, maintaining the existing behavior.
3. Compatibility with Current Plugins: This feature has been tested to be fully compatible with all current plugins,

Thank you for your time and for considering this contribution to the project. If you have any suggestions or remarks about the code changes, please feel free to comment here, and I will do my best to find a better solution.

Best regards,
Alex