Optimize Logger Class for Improved Readability and Efficiency

[singhtanishq]

Refactored the Logger class to enhance code readability and optimize logic while preserving functionality.

• Improved validation for add_result to ensure robust error handling.
• Modularized repetitive statistical calculations for reuse.
• Streamlined computation of statistics for all runs with concise helper functions.
• Simplified logic for better maintainability and clarity.