Version 0.2.0 Release with Enhanced UCX Support

[chnlkw]

Version 0.2.0 Release with Enhanced UCX Support

Summary

This PR introduces significant improvements to the async-ucx library, upgrading it to version 0.2.0 with enhanced UCX 1.18 compatibility and new features. Key changes include:

• Upgraded to UCX 1.18 with latest API compatibility
• Added AsyncRead/AsyncWrite support for Tag and Stream (requires util feature flag)
• Added connect_addr_vec function to Worker
• Migrated to Rust 2021 edition
• Improved error handling with Error to std::io::Error conversion
• Refactored endpoint implementations to use modern NBX APIs
• Enhanced documentation and examples

Detailed Changes

Core Improvements

• Migrated from legacy UCX APIs to modern NBX (Non-Blocking eXtended) APIs for better performance and feature support
• Added comprehensive error conversion from UCX errors to standard Rust io::Error types
• Introduced RequestParam builder pattern for cleaner API parameter construction
• Enhanced endpoint handling with new EndpointHandler type for safer endpoint management

New Features

• Added util feature flag with AsyncRead/AsyncWrite trait implementations for Stream and Tag APIs
• Added connect_addr_vec function to Worker for connecting to multiple addresses
• Added reply_ep() method to AM messages for easier reply endpoint handling
• Added handler() method to Endpoint for getting endpoint handlers
• Reduced Active Message ID from u32 to u16 to match UCX specifications

Documentation & Examples

• Significantly expanded README with comprehensive usage examples
• Added quick start guide with basic usage example
• Documented all feature flags (event, am, util)
• Improved code examples for RMA, Stream, Tag, and benchmarking

Code Quality

• Migrated to Rust 2021 edition
• Updated dependencies to compatible versions
• Improved code organization with better module structure
• Added comprehensive tests for stream functionality
• Fixed various bugs and issues throughout the codebase

Test Plan

• Verified all existing tests pass
• Tested new AsyncRead/AsyncWrite implementations
• Validated NBX API migrations don't break functionality
• Confirmed backward compatibility with existing code
• Ran benchmark tests to ensure performance parity

[chnlkw]

duplicated with #9