Construct JSON path only on exceptional cases.

[guidobrei]

This pull request addresses issue #63: Excessive object and memory allocations from string format operations during JSON logic evaluation.

Summary of Improvements

• Optimized jsonPath Construction:
  Now, jsonPath is built only when exceptions are thrown, not on every evaluation step.
• Reduced Usage of String.format:
  Frequent string formatting—previously responsible for a large portion of memory allocation—is now minimized.
• Efficient String Manipulation:
  Refactored string handling within the evaluation logic for improved efficiency.
• Decreased Unnecessary Object Creation:
  Memory profiles should reflect reduced object churn and overall improved allocation patterns.
• No breaking changes: The public interfaces have not been changed. The change should not break any dependent library.

Benefits

• Lower Memory Footprint:
  Dramatically reduces allocations related to string operations, easing runtime memory pressure.
• Improved Performance:
  Faster evaluations due to fewer expensive object and string operations.
• Better Scalability:
  Enhanced library stability and efficiency under heavy or high-throughput usage.
• Targeted Exception Diagnostics:
  jsonPath remains available for error handling and diagnostics, but is computed only as needed.