Add execution history in executor

[yaythomas]

Context

Complete the incomplete implementation in executor

Technical Requirements

• Complete the incomplete implementation in executor
• Add proper event generation from operations
• Implement paging for large histories

Implementation Details

• File: src/aws_durable_execution_sdk_python_testing/executor.py:403

Acceptance Criteria

• Incomplete implementation completed in executor
• Proper event generation from operations added
• Paging implemented for large histories