Feature Request: Add File Upload/Download Functionality

[iamxvbaba]

Description: I would like to propose adding built-in support for file upload and download operations.

Motivation:

• Simplify implementation of file handling features
• Provide a standard way to handle common file operations
• Reduce boilerplate code for developers

Suggested Implementation:

• Support multipart/form-data uploads
• Add stream-based file download handling
• Include progress tracking capabilities
• Add configurable file size limits
• Provide validation helpers for file types

[shenghui0779]

Good suggestion！