Add V2 Records API

[micahbf]

Add V2 Records API Client with Streaming Support

This PR introduces a new V2 Records API client that provides enhanced functionality for handling records with streaming capabilities.

Key Features

New V2 Records Client (src/v2/records/)

• Streaming Support: Implements both streaming read and write operations for large datasets
• Raw JSONL Interface: Direct access to JSONL formatted records for maximum performance

API Methods

Reading Records

• getRaw() - Fetch raw JSONL records
• getRawStreaming() - Stream raw JSONL records

Writing Records

• writeRaw() - Write raw JSONL records
• writeRawStreaming() - Stream write with chunking support

Integration

• Added v2 property to existing Records client for seamless access
• Comprehensive test coverage with 1000+ lines of tests
• Fixture data for testing record conversion and streaming

Technical Implementation

• Environment detection for streaming request body support
• Fallback mechanisms for environments without streaming support
• Proper error handling and logging
• Type definitions for all new interfaces and methods

This enhancement provides developers with more efficient ways to handle large datasets while maintaining full compatibility with existing APIs.