Build PyPI Package: near-py-utils - Python NEAR Utilities

Description

## Overview
Create a Python package with essential utilities for NEAR development - account handling, transaction building, and RPC helpers.

## Why This Matters
Python developers need native tools. This package provides Pythonic interfaces for common NEAR operations.

## Technical Requirements
- Account ID validation and formatting
- Transaction construction helpers
- RPC client with retry logic
- Type hints throughout
- Async support

## Deliverables
1. PyPI package: near-py-utils
2. Comprehensive utilities
3. Full type hints
4. Documentation with examples