Optimize API Parameter Documentation and Memory Usage

Motivation

The current implementation of parameter documentation in Grape can lead to unnecessary memory usage, especially for internal APIs where documentation is not required. This PR aims to optimize the way parameters are documented and stored, reducing memory footprint and improving efficiency.

Summary of Changes

• Refactored ParamsDocumentation module in lib/grape/validations/params_documentation.rb to:
  • Only document parameters when documentation is needed (i.e., when do_not_document is not set in the namespace).
  • Clean up attributes to avoid storing unnecessary data in RAM for internal or undocumented APIs.
  • Use a more efficient TypeCache for type stringification, reducing repeated computation and memory usage.
  • Improved the extraction of parameter details, ensuring only relevant information is kept and documented.
  • Added support for except_values in parameter documentation, which was previously missing. Now, parameters that specify except_values will have this information included in the documentation output.
• The changes are fully backward compatible for users who rely on parameter documentation, but provide a significant optimization for those who do not.

Impact

• Performance: Reduces memory usage for APIs that do not require parameter documentation.
• Maintainability: The code is now cleaner and easier to extend for future documentation or validation features.
• Documentation Completeness: Parameters with except_values are now properly documented, improving the accuracy and completeness of generated API docs.
• Backward Compatibility: No breaking changes; all existing documentation features remain intact for public APIs.

Additional Notes

• This PR does not change any public API or configuration. It is an internal optimization.
• All existing tests pass, and no user-facing behavior is altered except for improved efficiency and more complete documentation.